As filed with the Securities and Exchange Commission on April 21, 2006

                                                     Registration No. 333-123712

                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                  ---------------------------------------------

                         POST-EFFECTIVE AMENDMENT NO. 1
                                       TO
                                    FORM S-8
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933

                  ---------------------------------------------

                               ENZO BIOCHEM, INC.
             (EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)

NEW YORK                                                              13-2866202
(STATE OR OTHER JURISDICTION                                    (I.R.S. EMPLOYER
OF INCORPORATION OR ORGANIZATION)                         IDENTIFICATION NUMBER)

60 EXECUTIVE BOULEVARD
FARMINGDALE, NEW YORK                                                      11735
(ADDRESS OF PRINCIPAL EXECUTIVE OFFICES)                              (ZIP CODE)

 AMENDED AND RESTATED ENZO BIOCHEM, INC. 2005 EQUITY COMPENSATION INCENTIVE PLAN
                    ENZO BIOCHEM, INC. 1999 STOCK OPTION PLAN
                    ENZO BIOCHEM, INC. 1994 STOCK OPTION PLAN
                            (FULL TITLE OF THE PLANS)

                                 BARRY W. WEINER
                               ENZO BIOCHEM, INC.
                             60 EXECUTIVE BOULEVARD
                              FARMINGDALE, NY 11735
                                 (631) 755-5500
 (NAME, ADDRESS , INCLUDING ZIP CODE, AND TELEPHONE NUMBER, INCLUDING AREA CODE,
                             OF AGENT FOR SERVICE)

                                    Copy to:

                              ROBERT H. COHEN, ESQ.
                             GREENBERG TRAURIG, LLP
                                 200 PARK AVENUE
                               NEW YORK, NY 10166
                             (212) 801-9200 (PHONE)
                              (212) 801-6400 (FAX)


                         CALCULATION OF REGISTRATION FEE


============================== =================== =========================== =========================== ===================
   Title of Each Class of      Amount to be        Proposed Maximum            Proposed Maximum            Amount of
 Securities to be Registered   Registered(1)(2)    Offering Price Per Share    Aggregate Offering Price    Registration Fee
============================== =================== =========================== =========================== ===================
                                                                                                  
Common Stock,                     1,000,000(3)              $14.56(4)                  $14,560,000            $1,714.00(5)
par value $0.01 per share
============================== =================== =========================== =========================== ===================




(1)  Pursuant to Rule 416(a) under the Securities Act of 1933, as amended (the
     "Securities Act"), this Registration Statement shall also cover such
     indeterminate number of additional shares as may be issued to prevent
     dilution resulting from stock splits, stock dividends, or similar
     transactions.

(2)  Pursuant to Rule 429 of the Securities Act, the prospectus contained herein
     also relates to (i) 1,154,731 shares of common stock previously registered
     on Form S-8, Registration No. 333-87153, and (ii) 1,157,625 shares of
     common stock previously registered on Form S-8, Registration No. 333-89308,
     in each case issuable upon exercise of options granted or available to be
     granted under the Enzo Biochem, Inc. 1999 Stock Option Plan, and 1,336,745
     shares of common stock previously registered on Form S-8, Registration No.
     33-88826, issued or issuable upon exercise of options granted or available
     to be granted under the Enzo Biochem, Inc. 1994 Stock Option Plan.

(3)  Represents shares issuable upon the exercise of stock options, restricted
     stock awards and restricted stock unit awards granted or available to be
     granted under the Amended and Restated Enzo Biochem, Inc. 2005 Equity
     Compensation Incentive Plan.

(4)  Estimated solely for the purpose of determining the amount of the
     registration fee pursuant to Rule 457(c) under the Securities Act, based on
     the average of the high and low prices of the Company's common stock on the
     New York Stock Exchange on March 29, 2005.

(5)  No additional securities are being registered in this Post-Effective
     Amendment No. 1 to Registration Statement on Form S-8. The registration fee
     of $1,714.00 relating to the registration of 1,000,000 shares of the
     registrant's common stock issuable under the Amended and Restated Enzo
     Biochem, Inc. 2005 Equity Compensation Incentive Plan was previously paid
     in connection with the initial filing of this Registration Statement on
     Form S-8 on March 31, 2005. Therefore, no additional registration fee is
     required to be paid in connection with the filing of this Post-Effective
     Amendment No. 1.

AS PERMITTED BY RULE 429 UNDER THE SECURITIES ACT OF 1933, AS AMENDED, THE
RE-OFFER PROSPECTUS FILED AS PART OF THIS POST-EFFECTIVE AMENDMENT NO. 1 TO
REGISTRATION STATEMENT ON FORM S-8 IS A COMBINED RESALE PROSPECTUS WHICH SHALL
BE DEEMED A POST-EFFECTIVE AMENDMENT TO THE REGISTRANT'S REGISTRATION STATEMENTS
ON FORM S-8, REGISTRATION NOS. 33-88826, 333-87153 AND 333-89308.



                               EXPLANATORY NOTES:

         On March 31, 2005, Enzo Biochem, Inc. (the "Registrant") filed this
Registration Statement, prepared in accordance with the requirements of Form S-8
under the Securities Act (the "Original Registration Statement"), with the
Securities and Exchange Commission (the "SEC") to register the issuance of up to
1,000,000 shares of the Registrant's common stock pursuant to the Enzo Biochem,
Inc. 2005 Equity Compensation Incentive Plan (the "2005 Plan"), and to file a
re-offer prospectus (prepared in accordance with the requirements of Part I of
Form S-3 and pursuant to General Instruction C of Form S-8) to be used for
re-offers and resales of the Registrant's common stock acquired by persons who
may be deemed "affiliates" of the Registrant, as that term is defined in Rule
405 under the Securities Act, upon the exercise of stock options or receipt of
stock awards granted or available to be granted under the 2005 Plan, upon the
exercise of stock options granted or available to be granted under the Enzo
Biochem, Inc. 1999 Stock Option Plan (the "1999 Plan") or upon the exercise of
stock options granted or available to be granted under the Enzo Biochem, Inc.
1994 Stock Option Plan (the "1994 Plan").

         On January 27, 1995, the Registrant filed a Registration Statement on
Form S-8 (Registration No. 33-88826) to register under the Securities Act the
issuance of up to 950,000 shares of the Registrant's common stock upon exercise
of stock options issued or issuable under the 1994 Plan. As a result of 5% stock
dividends issued in each of the Registrant's fiscal years ended July 31, 1995,
1996, 1998 and 2001 to 2004, such 950,000 shares became 1,336,745 shares of the
Registrant's common stock.

         On September 15, 1999, the Registrant filed a Registration Statement on
Form S-8 (Registration No. 333-87153) to register under the Securities Act the
issuance of up to 950,000 shares of the Registrant's common stock upon exercise
of stock options issued or issuable under the 1999 Plan. As a result of 5% stock
dividends issued in each of the Registrant's fiscal years ended July 31, 2001 to
2004, such 950,000 shares became 1,154,731 shares of the Registrant's common
stock.

         On May 29, 2002, the Registrant filed a Registration Statement on Form
S-8 (Registration No. 333-89308) to register under the Securities Act the
issuance of up to 1,000,000 shares of common stock upon exercise of stock
options issued or issuable pursuant to an amendment to the 1999 Plan. As a
result of 5% stock dividends issued in each of the Registrant's fiscal years
ended July 31, 2002 to 2004, such 1,000,000 shares became 1,157,625 shares of
the Registrant's common stock.

         As permitted by Rule 429 under the Securities Act, the re-offer
prospectus filed as part of the Original Registration Statement (the "Original
Re-offer Prospectus") is a combined resale prospectus which shall be deemed a
post-effective amendment to the Registrant's Registration Statements on Form
S-8, Registration Nos. 33-88826, 333-87153 and 333-89308.

         On October 31, 2005, the Registrant's Board of Directors amended and
restated the 2005 Plan (as amended and restated, the "Amended 2005 Plan") among
other things to (a) permit restricted stock unit awards to be made, (b) add
specific performance criteria that may be used to establish performance
objectives for awards intended to qualify as "performance-based compensation"
under Section 162(m) of the Internal Revenue Code of 1986, as amended, (c)
eliminate automatic annual option grants to the Registrant's non-employee
directors and (d) make certain other related changes to the 2005 Plan. Because
the amendment to add specific performance criteria for Section 162(m) purposes
required shareholder ratification and approval, the Registrant's shareholders
were asked to ratify and approve the Amended 2005 Plan at the Registrant's 2006
Annual Meeting of Shareholders. On January 9, 2006, the Registrant's
shareholders ratified and approved the Amended 2005 Plan. Effective January 9,
2006, the Board of Directors awarded 10,000 restricted stock units to the
Registrant's Lead Independent Director and 5,000 restricted stock units to each
of the Registrant's other independent directors under the Amended 2005 Plan. In
April 2006, the Board of Directors awarded 4,000 restricted stock units to an
officer of the Registrant.

         This Amendment No. 1 to the Original Registration Statement ("Amendment
No. 1") is being filed with the SEC for the purpose of (i) amending the Original
Registration Statement to reflect the recent amendments to the 2005 Plan
contained in the Amended 2005 Plan and to file a true and complete copy of the
Amended 2005 Plan as an exhibit and (ii) amending the Original Re-offer
Prospectus to reflect the recent amendments to the 2005 Plan contained in the
Amended 2005 Plan and to add additional shares of the Registrant's common stock
thereto as a result of the award by the Registrant's Board of Directors of
10,000 restricted stock units to the Registrant's Lead Independent Director,
5,000 restricted stock units to each of the Registrant's other independent
directors and 4,000 restricted stock units to an officer of the Registrant under
the Amended 2005 Plan, which independent directors and officer are named as
"selling stockholders" in the Original Re-offer



Prospectus (as so amended, the "Amended Re-Offer Prospectus"). This Amendment
No. 1 is not being filed to register any additional shares of the Registrant's
common stock.

         As permitted by Rule 429 under the Securities Act, the Amended Re-Offer
Prospectus filed as part of this Amendment No. 1 is a combined resale prospectus
which shall be deemed a post-effective amendment to the Registrant's
Registration Statements on Form S-8, Registration Nos. 33-88826, 333-87153 and
333-89308.

                                     PART I

ITEM 1.  PLAN INFORMATION.

         The documents containing information specified by Part I of Form S-8
will be sent or given to holders of stock options, restricted stock awards or
restricted stock unit awards granted under the Amended 2005 Plan, as specified
in Rule 428(b)(1) promulgated by the SEC under the Securities Act. Such
document(s) are not required to be filed with the SEC but constitute (along with
the documents incorporated by reference into this Amendment No. 1 pursuant to
Item 3 of Part II hereof) a prospectus that meets the requirements of Section
10(a) of the Securities Act.

ITEM 2.  REGISTRANT INFORMATION AND EMPLOYEE PLAN ANNUAL INFORMATION.

         The Registrant will furnish without charge to each person to whom the
prospectus is delivered, upon the written or oral request of such person, a copy
of any and all of the documents incorporated by reference in Item 4 of Part II
of this Amendment No. 1, other than exhibits to such documents (unless such
exhibits are specifically incorporated by reference to the information that is
incorporated). Those documents are incorporated by reference in the Section
10(a) prospectus. Requests should be directed to Mr. Barry Weiner, at Enzo
Biochem, Inc., 60 Executive Boulevard, Farmingdale, New York 11735, telephone
number (631) 755-5500.

NOTE: The Amended Re-Offer Prospectus referred to in the Explanatory Notes
follows this page.



PROSPECTUS

                               ENZO BIOCHEM, INC.

                        2,216,991 SHARES OF COMMON STOCK


         This prospectus relates to the re-offer and resale of up to 2,216,991
shares of our common stock by certain selling stockholders who may be considered
our "affiliates." These selling stockholders have or may acquire these shares
upon the exercise of stock options or pursuant to restricted stock awards or
restricted stock units granted or available to be granted under our Amended and
Restated Enzo Biochem, Inc. 2005 Equity Compensation Incentive Plan, upon the
exercise of stock options granted or available to be granted under our Enzo
Biochem, Inc. 1999 Stock Option Plan, or upon the exercise of stock options
granted or available to be granted under our Enzo Biochem, Inc. 1994 Stock
Option Plan.

         Shares covered by this prospectus may be offered and sold from time to
time by or on behalf of the selling stockholders through brokers on the New York
Stock Exchange or otherwise at the prices prevailing at the time of such sales
or at prices otherwise negotiated. No specified brokers or dealers have been
designated by the selling stockholders and no agreement has been entered into in
respect of brokerage commissions or for the exclusive or coordinated sale of any
securities which may be offered pursuant to this prospectus. The net proceeds to
the selling stockholders will be the proceeds received by them upon such sales,
less brokerage commissions, if any. We will not receive any proceeds from these
sales. We will bear all expenses incurred in registering the shares, but all
commissions and other selling expenses incurred by each selling stockholder will
be borne by that stockholder.

         Our common stock is presently traded on the New York Stock Exchange
under the symbol "ENZ." The closing price per share of our common stock as
reported on the New York Stock Exchange Composite Transactions on April 20, 2006
was $12.94.

                           --------------------------

         INVESTING IN OUR COMMON STOCK INVOLVES MATERIAL RISKS. SEE "RISK
FACTORS" BEGINNING ON PAGE 4.

         Neither the Securities and Exchange Commission nor any state securities
commission has approved or disapproved of these securities or determined if this
prospectus is truthful or complete. Any representation to the contrary is a
criminal offense.

                 The date of this prospectus is April 21, 2006.



YOU SHOULD RELY ONLY ON THE INFORMATION CONTAINED IN THIS PROSPECTUS. WE HAVE
NOT AUTHORIZED ANYONE TO PROVIDE YOU WITH INFORMATION DIFFERENT FROM THAT
CONTAINED IN THIS PROSPECTUS. THIS PROSPECTUS IS NOT AN OFFER TO SELL, OR A
SOLICITATION OF AN OFFER TO BUY, SHARES OF COMMON STOCK IN ANY JURISDICTION
WHERE OFFERS AND SALES WOULD BE UNLAWFUL. THE INFORMATION CONTAINED IN THIS
PROSPECTUS IS COMPLETE AND ACCURATE ONLY AS OF THE DATE ON THE FRONT COVER OF
THIS PROSPECTUS, REGARDLESS OF THE TIME OF DELIVERY OF THIS PROSPECTUS OR OF ANY
SALE OF THE SHARES OF COMMON STOCK.


                           --------------------------

                                TABLE OF CONTENTS

                                                                            PAGE
                                                                            ----

SUMMARY........................................................................3

RISK FACTORS...................................................................4

SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS..............................9

USE OF PROCEEDS...............................................................10

SELLING STOCKHOLDERS..........................................................11

PLAN OF DISTRIBUTION..........................................................15

LEGAL MATTERS.................................................................16

EXPERTS.......................................................................16

WHERE YOU CAN FIND MORE INFORMATION...........................................16

INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE...............................16


                           --------------------------

         WE HAVE NOT TAKEN ANY ACTION TO PERMIT A PUBLIC OFFERING OF OUR SHARES
OF COMMON STOCK OUTSIDE OF THE UNITED STATES OR TO PERMIT THE POSSESSION OR
DISTRIBUTION OF THIS PROSPECTUS OUTSIDE OF THE UNITED STATES. PERSONS OUTSIDE OF
THE UNITED STATES WHO CAME INTO POSSESSION OF THIS PROSPECTUS MUST INFORM
THEMSELVES ABOUT AND OBSERVE ANY RESTRICTIONS RELATING TO THE OFFERING OF THE
SHARES OF COMMON STOCK AND THE DISTRIBUTION OF THIS PROSPECTUS OUTSIDE OF THE
UNITED STATES.

                                       2


                                     SUMMARY

         YOU SHOULD READ THE FOLLOWING SUMMARY TOGETHER WITH THE MORE DETAILED
INFORMATION CONTAINED ELSEWHERE IN THIS PROSPECTUS, INCLUDING THE SECTION TITLED
"RISK FACTORS," REGARDING OUR COMPANY AND THE COMMON STOCK BEING SOLD IN THIS
OFFERING.

THE COMPANY

         We are a leading life sciences and biotechnology company focused on
harnessing genetic processes to develop research tools, diagnostics and
therapeutics. We also provide diagnostic services to the medical community.
Since our formation in 1976, we have concentrated on developing enabling
technologies for detecting and identifying genes and for modifying gene
expression. These technologies are generally applicable to the diagnosis of
infectious and other diseases and form the basis for a portfolio of over 300
products marketed to the biomedical and pharmaceutical research markets. We are
further using these technologies as platforms for our planned entry into the
clinical diagnostics market. In addition, our work in gene analysis has led to
the development of significant therapeutic product candidates, several of which
are currently in clinical trials, and several are in preclinical studies. In the
course of our research and development activities, we have built what we believe
is a significant patent position (comprised of 42 issued U.S. patents, over 190
issued foreign patents and various pending applications worldwide) around our
core technologies.

         Our business activities are conducted through our three wholly owned
subsidiaries--Enzo Life Sciences, Inc., Enzo Therapeutics, Inc., and Enzo
Clinical Labs, Inc. These activities are: (1) research and development,
manufacturing and marketing of biomedical research products and tools through
Enzo Life Sciences and research and development of therapeutic products through
Enzo Therapeutics, and (2) the operation of a clinical reference laboratory
through Enzo Clinical Labs. Our primary sources of revenue have historically
been from sales of research products utilized in life science research and from
the clinical laboratory services provided to the healthcare community.

         Our principal executive offices are located at 60 Executive Boulevard,
Farmingdale, New York 11735, and our telephone number is (631) 755-5500.

                                       3


                                  RISK FACTORS

         AN INVESTMENT IN OUR COMMON STOCK INVOLVES A HIGH DEGREE OF RISK. YOU
SHOULD CAREFULLY CONSIDER THE FOLLOWING MATERIAL RISKS, TOGETHER WITH THE OTHER
INFORMATION CONTAINED IN THIS PROSPECTUS, BEFORE YOU DECIDE TO BUY OUR COMMON
STOCK. IF ANY OF THE FOLLOWING RISKS ACTUALLY OCCUR, OUR BUSINESS, RESULTS OF
OPERATIONS AND FINANCIAL CONDITION WOULD LIKELY SUFFER. IN THESE CIRCUMSTANCES,
THE MARKET PRICE OF OUR COMMON STOCK COULD DECLINE, AND YOU MAY LOSE ALL OR PART
OF YOUR INVESTMENT.

RISKS RELATING TO OUR COMPANY AND OUR INDUSTRIES

WE FACE INTENSE COMPETITION WHICH COULD CAUSE US TO DECREASE THE PRICES FOR OUR
PRODUCTS OR SERVICES OR RENDER OUR PRODUCTS UNECONOMICAL OR OBSOLETE, ANY OF
WHICH COULD REDUCE OUR REVENUES AND LIMIT OUR GROWTH.

         Our competitors in genetic engineering in the United States and abroad
are numerous and include major pharmaceutical, energy, food and chemical
companies, as well as specialized genetic engineering firms. Many of our large
competitors in genetic engineering have substantially greater resources than us
and have the capability of developing products which compete directly with our
products. Many of these companies are performing research in the same areas as
we are.

         Our clinical laboratory business is highly fragmented and intensely
competitive, and we compete with numerous national and local companies. Some of
these entities are larger than we are and have greater resources than we do. We
compete primarily on the basis of the quality of our testing, reporting and
information services, our reputation in the medical community, the pricing of
our services and our ability to employ qualified laboratory personnel.

         These competitive conditions could, among other things:

              o   Require us to reduce our prices to retain market share;

              o   Require us to increase our marketing efforts which could
                  reduce our profit margins;

              o   Increase our cost of labor to attract qualified laboratory
                  personnel;

              o   Render our biotechnology products uneconomical or obsolete; or

              o   Reduce our revenue.

WE ARE REQUIRED TO EXPEND SIGNIFICANT RESOURCES FOR RESEARCH AND DEVELOPMENT FOR
OUR PRODUCTS IN DEVELOPMENT AND THESE PRODUCTS MAY NOT BE DEVELOPED
SUCCESSFULLY. FAILURE TO SUCCESSFULLY DEVELOP THESE PRODUCTS MAY PREVENT US FROM
EARNING A RETURN ON OUR RESEARCH AND DEVELOPMENT EXPENDITURES.

         The products we are developing are at various stages of development and
clinical evaluations and may require further technical development and
investment to determine whether commercial application is practicable. There can
be no assurance that our efforts will result in products with valuable
commercial applications. Our cash requirements may vary materially from current
estimates because of results of our research and development programs,
competitive and technological advances and other factors. In any event, we will
require substantial funds to conduct development activities and pre-clinical and
clinical trials, apply for regulatory approvals and commercialize products, if
any, that are developed. We do not have any commitments or arrangements to
obtain any additional financing and there is no assurance that required
financing will be available to us on acceptable terms, if at all. Even if we
spend substantial amounts on research and development, our potential products
may not be developed successfully. If our product candidates on which we have
expended significant amounts for research and development are not
commercialized, we will not earn a return on our research and development
expenditures, which may harm our business.

PROTECTING OUR PROPRIETARY RIGHTS IS DIFFICULT AND COSTLY. IF WE FAIL TO
ADEQUATELY PROTECT OR ENFORCE OUR PROPRIETARY RIGHTS, WE COULD LOSE REVENUE.

         Our success depends in large part on our ability to obtain maintain and
enforce our patents. Our ability to commercialize any product successfully will
largely depend on our ability to obtain and maintain patents of sufficient scope
to prevent third parties from developing similar or competitive products. In the
absence of patent

                                       4


protection, competitors may impact our business by developing and marketing
substantially equivalent products and technology.

         Patent disputes are frequent and can preclude the commercialization of
products. We have in the past been, are currently, and may in the future be,
involved in material patent litigation, such as the matters discussed under
"Part I--Item 3. Legal Proceedings" in our Annual Report on Form 10-K for the
year ended July 31, 2004, which is incorporated by reference in this prospectus.
Patent litigation is time-consuming and costly in its own right and could
subject us to significant liabilities to third parties. In addition, an adverse
decision could force us to either obtain third-party licenses at a material cost
or cease using the technology or product in dispute.

         We have filed applications for United States and foreign patents
covering certain aspects of our technology, but there is no assurance that
pending patents will issue or as to the degree of protection which any issued
patent might afford. We also utilize certain unpatented proprietary technology.

LAWSUITS IN THE BIOTECHNOLOGY INDUSTRY ARE NOT UNCOMMON. IF WE BECOME INVOLVED
IN ANY SIGNIFICANT LITIGATION, WE WOULD SUFFER AS A RESULT OF THE DIVERSION OF
OUR MANAGEMENT'S ATTENTION, THE EXPENSE OF LITIGATION AND ANY JUDGMENTS AGAINST
US.

         In addition to intellectual property litigation, other substantial,
complex or extended litigation could result in large expenditures by us and
distraction of our management. For example, lawsuits by employees, stockholders,
collaborators or distributors could be very costly and substantially disrupt our
business. Disputes from time to time with companies or individuals are not
uncommon in the biotechnology industry, and we cannot assure you that we will
always be able to resolve them out of court.

WE MAY BE UNABLE TO OBTAIN OR MAINTAIN REGULATORY APPROVALS FOR OUR PRODUCTS
WHICH COULD REDUCE OUR REVENUE OR PREVENT US FROM EARNING A RETURN ON OUR
RESEARCH AND DEVELOPMENT EXPENDITURES.

         Our research, preclinical development, clinical trials, product
manufacturing and marketing are subject to regulation by the FDA and similar
health authorities in foreign countries. FDA approval is required for our
products, as well as the manufacturing processes and facilities, if any, used to
produce our products that may be sold in the United States. The process of
obtaining approvals from the FDA is costly, time consuming and often subject to
unanticipated delays. Even if regulatory approval is granted, such approval may
include significant limitations on indicated uses for which any products could
be marketed. Further, even if such regulatory approvals are obtained, a marketed
product and its manufacturer are subject to continued review, and later
discovery of previously unknown problems may result in restrictions on such
product or manufacturer, including withdrawal of the product from the market.

         New government regulations in the United States or foreign countries
also may be established that could delay or prevent regulatory approval of our
products under development. Further, because gene therapy is a relatively new
technology and has not been extensively tested in humans, the regulatory
requirements governing gene therapy products are uncertain and may be subject to
substantial further review by various regulatory authorities in the United
States and abroad. This uncertainty may result in extensive delays in initiating
clinical trials and in the regulatory approval process. Our failure to obtain
regulatory approval of their proposed products, processes or facilities could
have a material adverse effect on our business, financial condition and results
of operations. The proposed products under development may also be subject to
certain other federal, state and local government regulations, including, but
not limited to, the Federal Food, Drug and Cosmetic Act, the Environmental
Protection Act, and Occupational Safety and Health Act, and state, local and
foreign counterparts to certain of such acts.

         We cannot be sure that we can obtain necessary regulatory approvals on
a timely basis, if at all, for any of the products we are developing or
manufacturing or that we can maintain necessary regulatory approvals for our
existing products, and all of the following could have a material adverse effect
on our business:

              o   Significant delays in obtaining or failing to obtain required
                  approvals.

              o   Loss of, or changes to, previously obtained approvals.

              o   Failure to comply with existing or future regulatory
                  requirements.

                                       5


              o   Changes to manufacturing processes, manufacturing process
                  standards or Good Manufacturing Practices following approval
                  or changing interpretations of these factors.

OUR CLINICAL LABORATORY BUSINESS IS SUBJECT TO EXTENSIVE GOVERNMENT REGULATION
AND OUR LOSS OF ANY REQUIRED CERTIFICATIONS OR LICENSES COULD REQUIRE US TO
CEASE OPERATING THIS PART OF OUR BUSINESS, WHICH WOULD REDUCE OUR REVENUE AND
INJURE OUR REPUTATION.

         The clinical laboratory industry is subject to significant governmental
regulation at the Federal, state and local levels. Under the Clinical Laboratory
Improvement Act of 1967 and the Clinical Laboratory Improvement Amendments of
1988 (collectively, as amended "CLIA") virtually all clinical laboratories,
including ours, must be certified by the Federal government. Many clinical
laboratories also must meet governmental standards, undergo proficiency testing
and are subject to inspection. Certifications or licenses are also required by
various state and local laws. The failure of our clinical laboratory to obtain
or maintain such certifications or licenses under these laws could interrupt our
ability to operate our clinical laboratory business and injure our reputation.

REIMBURSEMENTS FROM THIRD-PARTY PAYORS, UPON WHICH OUR CLINICAL LABORATORY
BUSINESS IS DEPENDENT, ARE SUBJECT TO INCONSISTENT RATES AND COVERAGE AND
LEGISLATIVE REFORM THAT ARE BEYOND OUR CONTROL. THIS INCONSISTENCY AND ANY
REFORM THAT DECREASES COVERAGE AND RATES COULD REDUCE OUR EARNINGS AND HARM OUR
BUSINESS.

         Our clinical laboratory business is primarily dependent upon
reimbursement from third-party payors, such as Medicare (which principally
serves patients 65 and older) and Medicaid (which principally serves indigent
patients) and insurers. We are subject to variances in reimbursement rates among
different third-party payors, as well as constant renegotiation of reimbursement
rates. We also are subject to audit by Medicare and Medicaid which can result in
the return of payments made to us under these programs. These variances, rates
and audit results could reduce our margins and thus our earnings.

         The health care industry is undergoing significant change as
third-party payors increase their efforts to control the cost, utilization and
delivery of health care services. In an effort to address the problem of
increasing health care costs, legislation has been proposed or enacted at both
the Federal and state levels to regulate health care delivery in general and
clinical laboratories in particular. Some of the proposals include managed
competition, global budgeting and price controls. Changes that decrease
reimbursement rates or coverage, or increase administrative burdens on billing
third-party payors could reduce our revenues and increase our expenses.

THE CONTINUED GROWTH OF MANAGED CARE MAY REDUCE OUR REVENUES AND REDUCE OUR NET
EARNINGS.

         The number of individuals covered under managed care contracts or other
similar arrangements has grown over the past several years and may continue to
grow in the future. In addition, Medicare and Medicaid and other government
healthcare programs may continue to shift to managed care. Entities providing
managed care coverage have reduced payments for medical services, including
clinical laboratory services, in numerous ways such as entering into
arrangements under which payments to a service provider are capitated, limiting
testing to specified procedures, denying payment for services performed without
prior authorization and refusing to increase fees for specified services. These
trends reduce our revenues and limit our ability to pass cost increases to our
customers. Also, if these or other managed care organizations do not select us
as a participating provider, we may lose some or all of that business, which
could have an adverse effect on our business, financial condition and results of
operations.

COMPLIANCE WITH MEDICARE ADMINISTRATIVE POLICIES, INCLUDING THOSE PERTAINING TO
CERTAIN AUTOMATED BLOOD CHEMISTRY PROFILES, MAY REDUCE THE REIMBURSEMENTS WE
RECEIVE.

         Containment of health care costs, including reimbursement for clinical
laboratory services, has been a focus of ongoing governmental activity. In 1984,
Congress established the Medicare fee schedule for clinical laboratory services,
which is applicable to patients covered under Part B of the Medicare program as
well as patients receiving Medicaid. Clinical laboratories must bill Medicare
directly for the services provided to Medicare beneficiaries and may only
collect the amounts permitted under this fee schedule. Reimbursement to clinical
laboratories under the Medicare Fee Schedule has been steadily declining since
its inception. Furthermore, Medicare has mandated use of

                                       6


the Physicians Current Procedural Terminology, or CPT, for coding of laboratory
services which has altered the way we bill these programs for some of our
services, thereby reducing the reimbursement that we receive.

         In March 1996, HCFA (now, the Center for Medicare and Medicaid Services
or CMS) implemented changes in the policies used to administer Medicare payments
to clinical laboratories for the most frequently performed automated blood
chemistry profiles. Among other things, the changes established a consistent
standard nationwide for the content of the automated chemistry profiles. Another
change requires laboratories performing certain automated blood chemistry
profiles to obtain and provide documentation of the medical necessity of tests
included in the profiles for each Medicare beneficiary. Reimbursements have been
reduced as a result of this change. Because a significant portion of our costs
is fixed, these Medicare reimbursement reductions and changes have a direct
adverse effect on our net earnings and cash flows.

WE DEPEND ON KEY EMPLOYEES IN A COMPETITIVE MARKET FOR SKILLED PERSONNEL, AND
THE LOSS OF THE SERVICES OF ANY OF OUR KEY EMPLOYEES, INCLUDING OUR SENIOR
MANAGEMENT, COULD DELAY OUR RESEARCH AND DEVELOPMENT PROGRAMS AND WOULD
ADVERSELY AFFECT OUR ABILITY TO DEVELOP OUR BUSINESS.

         The specialized scientific nature of our business requires us to
attract and retain personnel with a wide variety of scientific capabilities.
There is intense competition in the biotechnology industry for qualified
scientific and technical personnel. To a large extent, our success in developing
proprietary technological products has been the result of the effective efforts
of our internal scientific staff and its experience and talent. Since our
inception an insignificant number of key employees have left us. We have key man
life insurance on Dr. Elazar Rabbani, our Chief Executive Officer, in the amount
of $3,000,000. There can be no assurance that we will continue to attract and
retain personnel of high scientific caliber. If we lose the services of our
management and scientific personnel and fail to recruit other scientific and
technical personnel, our research and development programs could be materially
and adversely delayed.

NEGATIVE PUBLICITY AND NEWS COVERAGE ABOUT US OR THE CLINICAL LABORATORY MAY
HARM OUR BUSINESS AND OPERATING RESULTS.

         In the past, the clinical laboratory industry has received negative
publicity. This publicity has led to increased legislation, regulation, and
review of industry practices. These factors may adversely affect our ability to
market our services, require us to change our services and increase the
regulatory burdens under which we operate, further increasing the costs of doing
business and adversely affecting our operating results.

OUR FUTURE SUCCESS WILL DEPEND IN PART UPON OUR ABILITY TO ENHANCE EXISTING
PRODUCTS AND TO DEVELOP AND INTRODUCE NEW PRODUCTS.

         The market for our products is characterized by rapidly changing
technology, evolving industry standards and new product introductions, which may
make our existing products obsolete. Our future success will depend in part upon
our ability to enhance existing products and to develop and introduce new
products.

         The development of new or enhanced products is a complex and uncertain
process requiring the accurate anticipation of technological and market trends
as well as precise technological execution. In addition, the successful
development of new products will depend on the development of new technologies.
We will be required to undertake time-consuming and costly development
activities and to seek regulatory approval for these new products. We may
experience difficulties that could delay or prevent the successful development,
introduction and marketing of these new products. Regulatory clearance or
approval of any new products may not be granted by the FDA or foreign regulatory
authorities on a timely basis, or at all, and the new products may not be
successfully commercialized.

OUR INABILITY TO CARRY OUT OUR CERTAIN OF OUR MARKETING AND SALES PLANS MAY MAKE
IT DIFFICULT FOR US TO GROW OR MAINTAIN OUR BUSINESS.

         During fiscal 2004, Enzo Life Sciences continued to implement an
aggressive marketing program designed to more directly service its end users,
while simultaneously positioning us for product line expansion. The program
involves continued increases in the direct field sales force, a comprehensive
advertising campaign, increased attendance at top industry trade meetings, and
publications in leading scientific journals, as well as the

                                       7


development of a new interactive web site. In addition to our direct sales, we
distribute our research products through leading producers of gene analysis
formats and other life sciences companies. If we are unable to successfully
implement these programs, we may be unable to grow and our business could
suffer.

BECAUSE OF COMPETITIVE PRESSURES AND THE COMPLEXITY AND EXPENSE OF THE BILLING
PROCESS IN OUR CLINICAL LABORATORY BUSINESS, WE MUST OBTAIN NEW CUSTOMERS WHILE
MAINTAINING EXISTING CUSTOMERS TO GROW OUR BUSINESS.

         Intense competition in the clinical laboratory business, increasing
administrative burdens upon the reimbursement process and reduced coverage and
payments by insurers make it necessary for us to increase our volume of
laboratory services. To do so, we must obtain new customers while retaining
existing customers. Our failure to attract new customers or the loss of existing
customers or a reduction in business from those customers could significantly
reduce our revenues and impede our ability to grow.


RISKS RELATING TO OUR COMMON STOCK

OUR STOCK PRICE IS VOLATILE, WHICH COULD RESULT IN SUBSTANTIAL LOSSES FOR
INVESTORS.

         Our common stock is quoted on the New York Stock Exchange, and there
has been substantial volatility in the market price of our common stock. The
trading price of our common stock has been, and is likely to continue to be,
subject to significant fluctuations due to a variety of factors, including:

     o   fluctuations in our quarterly operating and earnings per share results;

     o   the gain or loss of significant contracts;

     o   loss of key personnel;

     o   announcements of technological innovations or new products by us or our
         competitors;

     o   delays in the development and introduction of new products;

     o   legislative or regulatory changes;

     o   general trends in the industry;

     o   recommendations and/or changes in estimates by equity and market
         research analysts;

     o   biological or medical discoveries;

     o   disputes and/or developments concerning intellectual property,
         including patents and litigation matters;

     o   public concern as to the safety of new technologies;

     o   sales of common stock of existing holders;

     o   securities class action or other litigation;

     o   developments in our relationships with current or future customers and
         suppliers; and

     o   general economic conditions, both in the United States and abroad.

         In addition, the stock market in general has experienced extreme price
and volume fluctuations that have affected the market price of our common stock,
as well as the stock of many companies in our industries. Often, price
fluctuations are unrelated to operating performance of the specific companies
whose stock is affected.

         In the past, following periods of volatility in the market price of a
company's stock, securities class action litigation has occurred against the
issuing company. If we were subject to this type of litigation in the future, we
could incur substantial costs and a diversion of our management's attention and
resources, each of which could have a material adverse effect on our revenue and
earnings. Any adverse determination in this type of litigation could also
subject us to significant liabilities.

SALES OF A SUBSTANTIAL NUMBER OF SHARES OF COMMON STOCK IN THE PUBLIC MARKET
FOLLOWING THIS OFFERING COULD ADVERSELY AFFECT THE MARKET PRICE FOR OUR COMMON
STOCK.

         Registration statements filed by us with the SEC have been declared
effective with respect to significant amounts of our common stock. Sales of
common stock pursuant to such registration statements may have an adverse effect
on the market price of our common stock.

                                       8


BECAUSE WE DO NOT INTEND TO PAY CASH DIVIDENDS ON OUR COMMON STOCK, AN INVESTOR
IN OUR COMMON STOCK WILL BENEFIT ONLY IF IT APPRECIATES IN VALUE.

         We currently intend to retain our future earnings, if any, to finance
the expansion of our business and do not expect to pay any cash dividends on our
common stock in the foreseeable future. As a result, the success of an
investment in our common stock will depend entirely upon any future
appreciation. There is no guarantee that our common stock will appreciate in
value or even maintain the price at which an investor purchased her shares.

IT MAY BE DIFFICULT FOR A THIRD PARTY TO ACQUIRE US, WHICH COULD INHIBIT
STOCKHOLDERS FROM REALIZING A PREMIUM ON THEIR STOCK PRICE.

         We are subject to the New York anti-takeover laws regulating corporate
takeovers. These anti-takeover laws prohibit certain business combinations
between a New York corporation and any "interested shareholder" (generally, the
beneficial owner of 20% or more of the corporation's voting shares) for five
years following the time that the shareholder became an interested shareholder,
unless the corporation's board of directors approved the transaction prior to
the interested shareholder becoming interested.

         Our certificate of incorporation, as amended, and by-laws contain
provisions that could have the effect of delaying, deferring or preventing a
change in control of us that stockholders may consider favorable or beneficial.
These provisions could discourage proxy contests and make it more difficult for
stockholders to elect directors and take other corporate actions. These
provisions could also limit the price that investors might be willing to pay in
the future for shares of our common stock. These provisions include:

     o   a staggered board of directors, so that it would take three successive
         annual meetings to replace all directors; and

     o   advance notice requirements for the submission by stockholders of
         nominations for election to the board of directors and for proposing
         matters that can be acted upon by stockholders at a meeting.

                SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

         This prospectus contains "forward-looking statements" as defined in the
Private Securities Litigation Reform Act of 1995. All statements other than
statements of historical fact are "forward-looking statements." Forward-looking
statements may include the words "believes," "expects," "plans," "intends,"
"anticipates," "continues" or other similar expressions. These statements are
based on our current expectations of future events and are subject to a number
of risks and uncertainties that may cause our actual results to differ
materially from those described in the forward-looking statements. Should one or
more of these risks or uncertainties materialize, or should underlying
assumptions prove incorrect, actual results may vary materially from those
anticipated, estimated or projected. These factors and uncertainties include,
among others:

     o   Heightened competition, including the intensification of price
         competition.

     o   Impact of changes in payor mix, including the shift from traditional,
         fee-for-service medicine to managed-cost health care.

     o   Adverse actions by governmental or other third-party payors, including
         unilateral reduction of fee schedules payable to us.

     o   The impact upon our collection rates or general or administrative
         expenses resulting from compliance with Medicare administrative
         policies including specifically the HCFA's recent requirement that
         laboratories performing certain automated blood chemistry profiles
         obtain and provide documentation of the medical necessity of tests
         included in the profiles for each Medicare beneficiary.

     o   Failure to obtain new customers, retain existing customers or reduction
         in tests ordered or specimens submitted by existing customers.

     o   Adverse results in significant litigation matters.

                                       9


     o   Denial of certification or licensure of any of our clinical
         laboratories under CLIA, by Medicare programs or other Federal, state
         or local agencies.

     o   Adverse publicity and news coverage about us or the clinical laboratory
         industry.

     o   Inability to carry out marketing and sales plans.

     o   Loss or retirement of key executives.

     o   Impact of potential patent infringement by others or us.

     o   Inability to obtain patent protection or secure and maintain
         proprietary positions on our technology.

     o   Dependence on new technologies for our product development and
         dependence on product candidates in early stages of development.

     o   Clinical trials for our products will be expensive and their outcome is
         uncertain. We incur substantial expenses that might not result in
         viable products.

     o   May need additional capital in the future, and if unavailable, we may
         need to curtail or cease operations.

     o   Fluctuations in quarterly results resulting from uneven customer order
         flow.

         These and other risks and uncertainties are disclosed from time to time
in our filings with the Securities and Exchange Commission, in our press
releases and in oral statements made by or with the approval of authorized
personnel. We assume no obligation to update any forward-looking statements as a
result of new information or future events or developments.

                                 USE OF PROCEEDS

         The selling stockholders will receive all of the proceeds from the sale
of the shares of our common stock offered for sale by the selling stockholders
under this prospectus. We will receive none of the proceeds from the sale of the
shares by the selling stockholders. We will bear all expenses incurred in
registering the shares, but all commissions and other selling expenses incurred
by each selling stockholder will be borne by that stockholder.

                                       10


                              SELLING STOCKHOLDERS

         The shares of common stock to which this prospectus relates may be
reoffered and sold from time to time by selling stockholders who may be deemed
our "affiliates" (as defined in Rule 501(b) of Regulation D of the Securities
Act of 1933, as amended). The selling stockholders will acquire or have acquired
the shares of common stock upon exercise of options granted or to be granted to
them pursuant to the Amended and Restated Enzo Biochem, Inc. 2005 Equity
Compensation Incentive Plan ("Amended 2005 Plan") or Enzo Biochem, Inc. 1999
Stock Option Plan ("1999 Plan"), upon exercise of stock options granted under
our Enzo Biochem, Inc. 1994 Stock Option Plan ("1994 Plan" and, together with
the Amended 2005 Plan and the 1999 Plan, the "Plans") or pursuant to restricted
stock or restricted stock unit awards under the Amended 2005 Plan.

         The table below identifies each selling stockholder and his or her
relationship to us. The table also sets forth, as of April 21, 2006, for each
selling stockholder: (i) the number of shares of common stock beneficially owned
prior to this offering, (ii) the number of shares of common stock that may be
offered and sold through this prospectus, and (iii) the number of shares of
common stock and the percentage of the class represented by such shares to be
owned by each such selling stockholder assuming the sale of all of the
registered shares. There is no assurance that any of the selling stockholders
will sell any or all of their shares of common stock. The inclusion in the table
of the individuals named therein shall not be deemed to be an admission that any
such individuals are one of our affiliates. Except as otherwise noted, all
shares of common stock are beneficially owned and the sole investment and voting
power is held by the person named, and such persons' address is c/o Enzo
Biochem, Inc., 60 Executive Boulevard, Farmingdale, New York 11735. Information
regarding the selling stockholders, including the number of shares offered for
sale, may change from time to time, and any changed information will be set
forth in a prospectus supplement to the extent required.



                                                                                           BENEFICIAL OWNERSHIP
                                                                                           AFTER THIS OFFERING
                                                                                           -------------------
                                                     BENEFICIAL        SHARES THAT MAY
                                                 OWNERSHIP PRIOR TO     BE OFFERED AND    NUMBER OF      PERCENT OF
            NAME AND POSITION                     THIS OFFERING(1)      SOLD HEREBY(2)    SHARES(3)        CLASS(4)
-----------------------------------------------------------------------------------------------------------------------
                                                                                                 
Elazar Rabbani, Ph.D.                               2,249,941 (5)           523,342       1,726,599          5.4%
     Chairman of the Board and Chief
     Executive Officer

Shahram K. Rabbani                                  2,177,405 (6)           523,342       1,654,063          5.1%
     Chief Operating Officer, Secretary
     and Director

Barry W. Weiner                                     1,432,966 (7)           523,342        909,624           2.8%
     President, Chief Financial Officer
     and Director

Dean Engelhardt, Ph.D.                                249,597 (8)            72,386        177,211            *
     Executive Vice President

Norman E. Kelker, Ph.D.                               173,725 (9)            58,365        115,360            *
     Senior Vice President

John J. Delucca                                        85,324 (10)           85,324           --              --
     Director

Irwin C. Gerson                                        59,690 (11)           59,690           --              --
     Director

Melvin F. Lazar, CPA                                   75,394 (12)           38,644         36,750            *
     Director

John B. Sias                                          179,379 (13)           94,896         84,483            *
     Director


                                       11




                                                                                           BENEFICIAL OWNERSHIP
                                                                                           AFTER THIS OFFERING
                                                                                           -------------------
                                                     BENEFICIAL        SHARES THAT MAY
                                                 OWNERSHIP PRIOR TO     BE OFFERED AND    NUMBER OF      PERCENT OF
            NAME AND POSITION                     THIS OFFERING(1)      SOLD HEREBY(2)    SHARES(3)        CLASS(4)
-----------------------------------------------------------------------------------------------------------------------
                                                                                                 
Marcus A. Conant, M.D.                                 31,458 (14)           31,458           --              --
     Director

Herb Bass                                             203,044 (15)           62,668        140,376            *
     Vice President - Finance

David Goldberg                                        113,602 (16)           77,373         36,229            *
     Vice President - Business
    Development

Barbara Thalenfeld                                     81,997 (17)           66,161         15,836            *
     Vice President - Corporate
     Development


--------------------------

(1)  Beneficial owner means any person who, directly or indirectly, through any
     contract arrangement, understanding, relationship or otherwise has or
     shares: (i) voting power, which includes the power to vote, or to direct
     the voting of, shares of our common stock; and/or (ii) investment power,
     which includes the power to dispose, or to direct the disposition of,
     shares of our common stock. While under SEC rules, a person is also deemed
     to be a beneficial owner of a security if that person has the right to
     acquire beneficial ownership of such security at any time within 60 days
     from April 21, 2006, the date of this prospectus, the number of shares in
     this column includes (A) all shares of Enzo's common stock owned by the
     Selling Stockholder as of the date of this prospectus, (B) all shares of
     restricted stock or shares of common stock subject to restricted stock unit
     awards granted to the Selling Stockholder under the Amended 2005 Plan,
     whether or not such shares of restricted stock or restricted stock units
     have vested or will vest within 60 days after the date of this prospectus,
     and (C) all shares of common stock which the Selling Stockholder has the
     right to acquire through the exercise of options, including those granted
     under the Plans, warrants or other rights to purchase shares of common
     stock, whether or not such option, warrant or other right has yet become
     exercisable or will become exercisable within 60 days after the date of
     this prospectus.

(2)  The number of shares in this column includes (i) certain shares of Enzo's
     common stock acquired by the Selling Stockholder under the Plans as of the
     date of this prospectus, (ii) all shares of restricted stock or shares of
     common stock subject to restricted stock unit awards granted to the Selling
     Stockholder under the Amended 2005 Plan, whether or not such shares of
     restricted stock or restricted stock units have vested or will vest within
     60 days after the date of this prospectus, and (iii) all shares of Enzo's
     common stock which the Selling Stockholder has the right to acquire through
     the exercise of options granted under the Plans, whether or not such right
     has yet become exercisable or will become exercisable within 60 days after
     the date of this prospectus.

(3)  Assumes the sale of all shares of common stock registered pursuant to this
     prospectus, although selling stockholders are under no obligation known to
     us to sell any shares of common stock at this time. The number of shares in
     this column includes (i) shares of Enzo's common stock acquired by the
     Selling Stockholder, other than those granted under the Plan, and (ii)
     shares of common stock which the Selling Stockholder has the right to
     acquire through the exercise of options, other than those granted under the
     Plans, warrants or other rights to purchase shares of common stock within
     60 days after the date of this prospectus.

(4)  Percentage calculated on the basis of 32,249,634 shares of common stock
     outstanding at April 21, 2006, plus in the case of each selling
     stockholder, additional shares of common stock deemed to be outstanding
     because such shares may be acquired through the exercise of outstanding
     options beneficially owned by such selling stockholder.

(5)  Includes (i) 63,814 shares of common stock issuable upon the exercise of
     options issued under the 1994 Plan,

                                       12


     all of which are currently exercisable, (ii) 409,528 shares of common stock
     issuable upon the exercise of options issued under the 1999 Plan, of which
     381,956 are currently exercisable and 27,563 have not yet become
     exercisable as of April 21, 2006, (iii) 50,000 shares of common stock
     issuable upon the exercise of options issued under the Amended 2005 Plan,
     all of which are currently exercisable, (iv) 3,469 shares of common stock
     held in the name of Dr. Rabbani as custodian for certain of his children,
     (v) 2,168 shares of common stock held in the name of Dr. Rabbani's wife as
     custodian for certain of their children, and (vi) 4,215 shares of common
     stock held in the Enzo Biochem, Inc. 401(k) plan.

(6)  Includes (i) 63,814 shares of common stock issuable upon the exercise of
     options issued under the 1994 Plan, all of which are currently exercisable,
     (ii) 409,528 shares of common stock issuable upon the exercise of options
     under the 1999 Plan, of which 381,965 are currently exercisable and 27,563
     have not yet become exercisable as of April 21, 2006, (iii) 50,000 shares
     of common stock issuable upon the exercise of options issued under the
     Amended 2005 Plan, all of which are currently exercisable, (iv) 614 shares
     of common stock held in the name of Mr. Rabbani's son, (v) 1,671 shares of
     common stock that Mr. Rabbani holds as custodian for certain of his
     nephews, and (vi) 4,180 shares of common stock held in the Enzo Biochem,
     Inc. 401(k) plan.

(7)  Includes (i) 63,814 shares of common stock issuable upon the exercise of
     options issued under the 1994 Plan, all of which are currently exercisable,
     (ii) 409,528 shares of common stock issuable upon the exercise of options
     under the 1999 Plan, of which 381,965 are currently exercisable and 27,563
     have not yet become exercisable as of April 21, 2006, (iii) 50,000 shares
     of common stock issuable upon the exercise of options issued under the
     Amended 2005 Plan, all of which are currently exercisable, (iv) 3,642
     shares of common stock which Mr. Weiner holds as custodian for certain of
     his children, and (v) 4,223 shares of common stock held in the Enzo
     Biochem, Inc. 401(k) plan.

(8)  Includes (i) 12,155 shares of common stock issuable upon the exercise of
     options issued under the 1994 Plan, all of which are currently exercisable,
     (ii) 50,231 shares of common stock issuable upon the exercise of options
     under the 1999 Plan, of which 46,097 are currently exercisable and 4,134
     have not yet become exercisable as of April 21, 2006, (iii) 10,000 shares
     of common stock issuable upon the exercise of options issued under the
     Amended 2005 Plan, all of which are currently exercisable, (iv) 5,310
     shares of common stock held in the Enzo Biochem, Inc. 401(k) plan, and (v)
     7,036 shares of common stock issued upon the exercise of options granted
     under the 1994 Plan.

(9)  Includes (i) 12,155 shares of common stock issuable upon the exercise of
     exercisable options issued under the 1994 Plan, all of which are currently
     exercisable, (ii) 36,210 shares of common stock issuable upon the exercise
     of options under the 1999 Plan, of which 33,454 are currently exercisable
     and 2,756 have not yet become exercisable as of April 21, 2006, (iii)
     10,000 shares of common stock issuable upon the exercise of options issued
     under the Amended 2005 Plan, all of which are currently exercisable, and
     (iv) 4,132 shares of common stock held in the Enzo Biochem, Inc. 401(k)
     plan.

(10) Includes (i) 5,000 shares of common stock underlying restricted stock units
     granted to Mr. Delucca under the Amended 2005 Plan, (ii) 15,650 shares of
     common stock issuable upon the exercise of exercisable options under the
     1994 Plan, all of which are currently exercisable, and (iii) 64,584 shares
     of common stock issuable upon the exercise of options under the 1999 Plan,
     all of which are currently exercisable.

(11) Includes (i) 5,000 shares of common stock underlying restricted stock units
     granted to Mr. Gerson under the Amended 2005 Plan, and (ii) 54,690 shares
     of common stock issuable upon the exercise of exercisable options under the
     1999 Plan, all of which are currently exercisable.

(12) Includes (i) 10,000 shares of common stock underlying restricted stock
     units granted to Mr. Lazar under the Amended 2005 Plan, (ii) 28,644 shares
     of common stock issuable upon the exercise of exercisable options under the
     1999 Plan, all of which are currently exercisable, (iii) 7,875 shares of
     common stock owned by Mr. Lazar's wife, and (iv) 3,150 shares of common
     stock held in the name of a defined benefit plan for which Mr. Lazar is the
     sole trustee and beneficiary.

(13) Includes (i) 5,000 shares of common stock underlying restricted stock units
     granted to Mr. Sias under the Amended 2005 Plan, (ii) 35,775 shares of
     common stock issuable upon the exercise of exercisable options issued under
     the 1994 Plan, all of which are currently exercisable, (iii) 54,121 shares
     of common stock issuable

                                       13


     upon the exercise of options under the 1999 Plan, all of which are
     currently exercisable, and (iv) 10,553 shares of common stock issued upon
     the exercise of options granted under the 1994 Plan.

(14) Includes (i) 5,000 shares of common stock underlying restricted stock units
     granted to Mr. Conant under the Amended 2005 Plan, and (ii) 26,458 shares
     of common stock issuable upon the exercise of options under the 1999 Plan,
     of which 18,583 are currently exercisable and 7,875 have not yet become
     exercisable as of April 21, 2006.

(15) Includes (i) 9,267 shares of common stock issuable upon the exercise of
     exercisable options issued under the 1994 Plan, all of which are currently
     exercisable, (ii) 39,401 shares of common stock issuable upon the exercise
     of options under the 1999 Plan, of which 36,645 shares are currently
     exercisable and 2,756 have not yet become exercisable as of April 21, 2005,
     (iii) 10,000 shares of common stock issuable upon the exercise of options
     issued under the Amended 2005 Plan, all of which are currently exercisable,
     (iv) 4,000 shares of common stock underlying restricted stock units granted
     to Mr. Bass under the Amended 2005 Plan, (v) 26,424 shares of common stock
     issued upon the exercise of options granted under the 1994 Plan, and (vi)
     4,055 shares of common stock held in the Enzo Biochem, Inc. 401(k) plan.

(16) Includes (i) 28,732 shares of common stock issuable upon the exercise of
     exercisable options issued under the 1994 Plan, all of which are currently
     exercisable, (ii) 38,641 shares of common stock issuable upon the exercise
     of options under the 1999 Plan, of which 35,885 shares are currently
     exercisable and 2,756 have not yet become exercisable as of April 21, 2006,
     (iii) 10,000 shares of common stock issuable upon the exercise of options
     issued under the Amended 2005 Plan, all of which are currently exercisable,
     and (iv) 3,102 shares of common stock held in the Enzo Biochem, Inc. 401(k)
     plan.

(17) Includes (i) 22,654 shares of common stock issuable upon the exercise of
     exercisable options issued under the 1994 Plan, all of which are currently
     exercisable, (ii) 33,507 shares of common stock issuable upon the exercise
     of options under the 1999 Plan, of which 30,751 shares are currently
     exercisable and 2,756 have not yet become exercisable as of April 21, 2006,
     (iii) 10,000 shares of common stock issuable upon the exercise of options
     issued under the Amended 2005 Plan, all of which have become exercisable,
     and (iv) 1,019 shares of common stock held in the Enzo Biochem, Inc. 401(k)
     plan.

*    Denotes less than 1%.

                                       14


                              PLAN OF DISTRIBUTION

         The shares of common stock covered by this prospectus are being
registered by us for the account of the selling stockholders.

         The shares of common stock offered hereby may be sold from time to time
directly by or on behalf of each selling stockholder in one or more transactions
on the New York Stock Exchange or on any stock exchange on which the common
stock may be listed at the time of sale, in privately negotiated transactions,
or through a combination of such methods, at market prices prevailing at the
time of sale, at prices related to such prevailing market prices, at fixed
prices (which may be changed) or at negotiated prices. The selling stockholder
may sell shares through one or more agents, brokers or dealers or directly to
purchasers. Such brokers or dealers may receive compensation in the form of
commissions, discounts or concessions from the selling stockholders and/or
purchasers of the shares or both. Such compensation as to a particular broker or
dealer may be in excess of customary commissions.

         In connection with their sales, a selling stockholder and any
participating broker or dealer may be deemed to be "underwriters" within the
meaning of the Securities Act of 1933, as amended ("Securities Act"), and any
commissions they receive and the proceeds of any sale of shares may be deemed to
be underwriting discounts and commissions under the Securities Act.

         We are bearing all costs relating to the registration of the shares of
common stock. Any commissions or other fees payable to broker-dealers in
connection with any sale of the shares will be borne by the selling stockholder
or other party selling such shares. In order to comply with certain states'
securities laws, if applicable, the shares may be sold in such jurisdictions
only through registered or licensed brokers or dealers. In certain states, the
shares may not be sold unless the shares have been registered or qualified for
sale in such state, or unless an exemption from registration or qualification is
available and is obtained or complied with. Sales of the shares must also be
made by the selling stockholders in compliance with all other applicable state
securities laws and regulations.

         In addition to any shares sold hereunder, selling stockholders may sell
shares of common stock in compliance with Rule 144 under the Securities Act.
There is no assurance that the selling stockholders will sell all or a portion
of the common stock offered hereby.

         The selling stockholders may agree to indemnify any broker-dealer or
agent that participates in transactions involving sales of the shares against
certain liabilities in connection with the offering of the shares arising under
the Securities Act of 1933.

         We have notified the selling stockholders of the need to deliver a copy
of this prospectus in connection with any sale of the shares.

                                       15


                                  LEGAL MATTERS

         The validity of the shares of common stock will be passed upon for us
by Greenberg Traurig, LLP, New York, New York.

                                     EXPERTS

         The consolidated financial statements of Enzo Biochem Inc. appearing in
Enzo Biochem Inc.'s Annual Report (Form 10-K) for the year ended July 31, 2005
including schedules appearing therein, and Enzo Biochem Inc. management's
assessment of the effectiveness of internal control over financial reporting as
of July 31, 2005 included therein, have been audited by Ernst & Young LLP,
independent registered public accounting firm, as set forth in their reports
thereon, included therein, and incorporated herein by reference. Such
consolidated financial statements and management's assessment are incorporated
herein by reference in reliance upon such reports given on the authority of such
firm as experts in accounting and auditing.

                       WHERE YOU CAN FIND MORE INFORMATION

         We have filed registration statements with the SEC on Forms S-8 to
register the shares of our common stock being offered by this prospectus. This
prospectus, which is part of the registration statements, does not contain all
the information included in the registration statements. Some information has
been omitted in accordance with the rules and regulations of the SEC. For
further information, please refer to the registration statements and the
exhibits and schedules filed with them. In addition, we file annual, quarterly
and current reports, proxy statements and other information with the SEC. You
may read and copy any reports, statements or other information that we file at
the SEC's public reference facilities at 450 Fifth Street, N.W., Washington,
D.C. 20549. Please call the SEC at 1-800-SEC-0330 for further information
regarding the public reference facilities. The SEC maintains a website,
http://www.sec.gov, that contains reports, proxy statements and information
statements and other information regarding registrants that file electronically
with the SEC, including us. Our SEC filings are also available to the public
from commercial document retrieval services. Information contained on our
website should not be considered part of this prospectus.

         You may also request a copy of our filings at no cost by writing or
telephoning us at:

                               Enzo Biochem, Inc.
                             60 Executive Boulevard
                           Farmingdale, New York 11735
                             Attention: Barry Weiner
                                 (631) 755-5500

                 INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE

         The SEC allows us to "incorporate by reference" the information we file
with them, which means that we can disclose important information to you by
referring you to those documents. The information incorporated by reference is
considered to be part of this prospectus, and information that we file later
with the SEC will automatically update and supersede this information. We
incorporate by reference the documents listed below and any future filings that
we will make with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the
Securities Exchange Act of 1934.

(a)      Our Annual Report on Form 10-K for the year ended July 31, 2005, filed
         on October 14, 2005.

(b)      Our Quarterly Reports on Form 10-Q for the quarter ended October 31,
         2005 filed on December 12, 2005 and for the quarter ended January 31,
         2006 filed on March 13, 2006; our Current Reports on Form 8-K filed on
         November 4, 2005, December 12, 2005, January 19, 2006 and March 14,
         2006; and our definitive proxy statement on Schedule 14A filed on
         November 28, 2005, relating to our Annual Meeting of Shareholders held
         on January 9, 2006.

(c)      The description of our shares of common stock contained in our
         registration statement on Form 8-A, as filed with the SEC on December
         8, 1999.

                                       16


         We will provide without charge to each person, including any beneficial
owner, to whom a copy of this prospectus is delivered a copy of any or all
documents incorporated by reference into this prospectus except the exhibits to
such documents (unless such exhibits are specifically incorporated by reference
in such documents). Requests for copies can be made by writing or telephoning us
at: Enzo Biochem, Inc., 60 Executive Boulevard, Farmingdale, New York 11735,
Attention: Barry Weiner, telephone number: (631) 755-5500.

                                       17


                                     PART II
               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3.       INCORPORATION OF DOCUMENTS BY REFERENCE

         The following documents filed with the SEC are hereby incorporated by
reference into this Amendment No. 1 to Registration Statement on Form S-8:

(a)      Our Annual Report on Form 10-K for the year ended July 31, 2005, filed
         on October 14, 2005.

(b)      Our Quarterly Reports on Form 10-Q for the quarter ended October 31,
         2005 filed on December 12, 2005 and for the quarter ended January 31,
         2006 filed on March 13, 2006; our Current Reports on Form 8-K filed on
         November 4, 2005, December 12, 2005, January 19, 2006 and March 14,
         2006; and our definitive proxy statement on Schedule 14A filed on
         November 28, 2005, relating to our Annual Meeting of Shareholders held
         on January 9, 2006.

(c)      The description of our shares of common stock contained in our
         registration statement on Form 8-A, as filed with the SEC on December
         8, 1999.

         All documents subsequently filed by the Registrant pursuant to Sections
13(a), 13(c), 14 and 15(d) of the Securities Exchange Act of 1934, prior to the
filing of a post-effective amendment to this Registration Statement which
indicates that all securities offered hereby have been sold or which deregisters
all securities then remaining unsold, shall be deemed to be incorporated by
reference in this Registration Statement and to be part hereof from the date of
filing of such documents. Any statement contained in a document incorporated or
deemed to be incorporated by reference herein shall be deemed to be modified or
superseded for the purposes of this Registration Statement to the extent a
statement contained herein or in any other subsequently filed document which
also is or is deemed to be incorporated by reference herein modifies or
supersedes such statement. Any statement so modified or superseded shall not be
deemed, except as so modified or superseded, to constitute a part of this
Registration Statement.

ITEM 4.       DESCRIPTION OF SECURITIES.

         Not applicable.

ITEM 5.       INTERESTS OF NAMED EXPERTS AND COUNSEL.

         A shareholder of Greenberg Traurig, LLP, New York, New York, holds
options to acquire an aggregate of 55,254 shares of the Registrant's common
stock.

ITEM 6.       INDEMNIFICATION OF DIRECTORS AND OFFICERS

         The registrant is a New York corporation. Sections 721 through 726 of
the New York Business Corporation Law (the "BCL") provide that, in certain
circumstances, a corporation may indemnify its directors and officers against
judgments, fines, amounts paid in settlement and reasonable expenses, including
attorneys' fees, actually and necessarily incurred as a result of any actual or
threatened action or proceeding against such directors or officers, or by or in
the right of any other enterprise which such directors or officers served in any
capacity at the request of the corporation, by reason of the fact that such
person acted in any of the capacities set forth above, if such director or
officer (i) acted, in good faith, for a purpose which he or she reasonably
believed to be in or not opposed to the best interests of the corporation and
(ii) in criminal actions or proceedings, had no reasonable cause to believe that
his or her conduct was unlawful; provided, however, that no indemnification may
be provided where a final adjudication adverse to the director or officer
establishes that his or her actions were committed in bad faith or were the
result of active and deliberate dishonesty and were material to the cause of
action adjudicated, or that he or she personally gained a financial profit or
other advantage to which he or she was not legally entitled. A corporation is
required to indemnify against reasonable expenses (including attorneys' fees)
incurred by any director or officer who successfully defends any such action.
The BCL also provides for indemnification of officers and directors in actions

                                      II-1


by or in the right of the corporation, subject to certain exceptions.
Indemnification provided by these provisions of the BCL is not exclusive of any
other rights to which a director or officer may be entitled. The foregoing
statements are subject to the detailed provisions of the BCL.

         The registrant's Certificate of Incorporation states the following:

         "Article 8. The Corporation shall, to the fullest extent permitted by
the Business Corporation Law of the States of New York, indemnify any and all
persons whom it shall have power to indemnify from and against any and all of
the expenses, liabilities or other matters as provided under Articles of Seven
of the Business Corporation Law of the State of New York."

         "Article 12. No director of the Corporation shall be liable to the
Corporation or its shareholders for damage for any breach of duty in such
capacity, provided that nothing contained in this Article shall eliminate or
limit the liability of a director (i) if a judgment or other final adjudication
adverse to him establishes that his acts or omissions were in bad faith or
involved acts or omissions were in bad faith or involved intentional misconduct
or a knowing violation of law or that he personally gained in fact a financial
profit or other advantage to which he was not legally entitled or that his acts
violated Section 719 of the New York Business Corporation Law or (ii) for any
act or omission prior to July 8, 1988."

         ARTICLE V of the registrant's By-Laws provides as follows:

         "Section 1. INDEMNIFICATION-THIRD PARTY AND DERIVATIVE ACTIONS.

         (a) The Corporation shall indemnify any person made, or threatened to
be made, a party to an action or proceeding (other than one by or in the right
of the Corporation to procure a judgment in its favor), whether civil or
criminal, including an action by or in the right of any other corporation of any
type or kind, domestic or foreign, or any partnership, joint venture, trust,
employee benefit plan or other enterprise, which any director or officer of the
Corporation served in any capacity at the request of the Corporation, by reason
of the fact that he, his testator or intestate, is or was a director or officer
of the Corporation, by reason of the fact that he, his corporation, partnership,
joint venture, trust, employee benefit plan or other enterprise in any capacity,
against judgments, fines, amounts paid in settlement and expenses (including
attorneys' fees) incurred in connection with any such action or proceeding, or
any appeal therein, provided that no indemnification may be made to or on behalf
of such person if (i) his acts were committed in bad faith or were the result of
his active and deliberate dishonesty and were material to such action or
proceeding or (ii) he personally gained in fact a financial profit or other
advantage to which he was not legally entitled.

         (b) The Corporation shall indemnify any person made, or threatened to
be made, a party to an action by or in the right of the Corporation to procure a
judgment in its favor by reason of the fact that he, his testator or intestate,
is or was a director or officer of the Corporation, or is or was serving at the
request of the Corporation as a director or officer of any other corporation of
any type or kind, domestic or foreign, or of any partnership, joint venture,
trust, employee benefit plan or other enterprise, against judgments, fines,
amounts paid in settlement and expenses (including attorneys' fees) incurred in
connection with such action, or any appeal therein, provided that no
indemnification may be made to or on behalf of such person if (i) his acts were
committed in bad faith or were the result of his active and deliberate
dishonesty and were material to such action or (ii) he personally gained in fact
a financial profit or other advantage to which he was not legally entitled.

         (c) The termination of any civil or criminal action or proceeding by
judgment, settlement, conviction or upon a plea of nolo contendere, or its
equivalent, shall not in itself create a presumption that any such person has
not met the standard of conduct set forth in this Section 1.

         (d) For the purpose of this Section 1: (i) the Corporation shall be
deemed to have requested a person to serve an employee benefit plan where the
performance by such person of his duties to the Corporation also imposes duties
on, or otherwise involve services by, such person to the plan or participants or
beneficiaries of the plan; and (ii) excise taxes assessed on a person with
respect to an employee benefit plan pursuant to applicable law shall be
considered fines.

                                      II-2


         Section 2. PAYMENT OF INDEMNIFICATION; REPAYMENT.

         (a) A person who has been successful, on the merits or otherwise, in
the defense of a civil or criminal action or proceeding of the character
described in Section 1 of this Article V shall be entitled to indemnification as
authorized in such Section.

         (b) Except as provided in paragraph (a) of this Section 2, any
indemnification under Section 1 of this Article V, unless ordered by a court,
shall be made by the Corporation only if authorized in the specific case:

         (i) by the Board of Directors acting by a quorum consisting of
directors who are not parties to the action or proceeding giving rise to the
indemnity claim upon a finding that the director or officer has met the standard
of conduct set forth in Section 1 of this Article V; or (ii) if a quorum under
the foregoing clause (i) is not obtainable or, even if obtainable, a quorum of
disinterested directors so directs: (A) by the Board of Directors upon the
opinion in writing of independent legal counsel that indemnification is proper
in the circumstances because the standard of conduct set forth in Section 1 of
this Article V has been met by such director or officer, or (B) by the
shareholders of the Corporation upon a finding that the director or officer has
met such standard of conduct.

         (c) Expenses Incurred by a director or officer in defending a civil or
criminal action or proceeding shall be paid by the Corporation in advance of the
final disposition of such action or proceeding upon receipt of an undertaking by
or on behalf of such director or officer to repay such amount incase he is
ultimately found, in accordance with this Article V, not to be entitled to
indemnification or, where indemnity is granted, to the extent the expenses so
paid exceed the indemnification to which he is entitled.

         (d) Any indemnification of a director or officer of the Corporation
under Section 1 of this Article V, or advancement of expenses under paragraph
(c) of this Section 2, shall be made promptly, and in any event within 60 days,
upon the written request of the director of officer.

         Section 3. ENFORCEMENT; DEFENSES.

         The right to indemnification or advancement of expenses granted by this
Article V shall be enforceable by the director or officer in any court of
competent jurisdiction if the Corporation denies such request, in whole or in
part, or if no disposition thereof is made within 60 days after written request
by the director or officer. Such person's expenses incurred in connection with
successfully establishing his right to indemnification, in whole or in part, in
any such action shall also be indemnified by the Corporation. It shall be a
defense to any such action (other than an action brought to enforce a claim for
the advancement of expenses under Section 2 of this Article V where the required
undertaking has been received by the Corporation) that the claimant has not met
the standard of conduct set forth in Section 1 of this Article V, but the burden
of providing such defense shall be on the Corporation. Neither the failure of
the Corporation (including its Board of Directors, its independent legal
counsel, and its shareholders) to have made a determination that indemnification
of the claimant is proper in the circumstances, nor the fact that there has been
an actual determination by the Corporation (including its Board of Directors,
its independent legal counsel, and its shareholders) that indemnification of the
claimant is not proper in the circumstances, shall be a defense to the action or
create a presumption that the claimant is not entitled to indemnification.

         Section 4. SURVIVAL, SAVINGS CLAUSE; PRESERVATION OF OTHER RIGHTS.

         (a) The foregoing indemnification provisions shall be deemed to be a
contract between the Corporation and each director and officer who serves in
such capacity at any time while these provisions, as well as the relevant
provisions of the New York Business Corporation Law, are in effect and any
repeal or modification thereof shall not affect any right or obligation then
existing with respect to any state of facts then or previously existing or any
action or proceeding previously or thereafter brought or threatened based in
whole or in part upon any such state of facts. Such a contract fight may not be
modified retroactively without the consent of such director or officer.

         (b) If this Article V or any portion hereof shall be invalidated on any
ground by any court of competent jurisdiction, then the Corporation shall
nevertheless indemnify each director or officer of the Corporation against
judgments, fines, amounts paid in settlement and expenses (including attorneys'
fees) incurred in connection with any actual or threatened action or proceeding,
whether civil or criminal, including any actual or threatened action by

                                      II-3


or in the right of the Corporation, or any appeal therein, to the full extent
permitted by any applicable portion of this Article V that shall not have been
invalidated and to the full extent permitted by applicable law.

         (c) The indemnification provided by this Article V shall not be deemed
exclusive of any other rights to which those indemnified may be entitled under
any by-law, agreement, vote of shareholders or directors or otherwise, both as
to action in his official capacity and as to action in another capacity while
holding such office, and shall continue as to a person who has ceased to be a
director or officer and shall inure to the benefit of the heirs, executors and
administrators of such a person. The Corporation is hereby authorized to provide
further indemnification if it deems advisable by resolution of shareholders or
directors, by amendment of these by-laws or by agreement.

         Section 5. INSURANCE.

         The Corporation may purchase and maintain insurance:

         (a) to indemnify the Corporation for any obligation which it incurs as
a result of the indemnification of directors and officers under the provisions
of this Article V,

         (b) to indemnify directors and officers in instances in which they may
be indemnified by the Corporation under the provisions of this Article V, and

         (c) to indemnify directors and officers in instances in which they may
not otherwise be indemnified by the Corporation under the provisions of this
Article V, provided that the contract of insurance covering such directors and
officers pursuant to the foregoing paragraph (c) of Section 4 of this Article V
shall provide, in a manner acceptable to the superintendent of insurance, for
retention amount and for co-insurance, and provided, further, that no insurance
under this Article V may provide for any payment, other than the cost of
defense, to or on behalf of any director or officer if a judgment or other final
adjudication adverse to the insured director or officer establishes (i) that his
acts of active and deliberate dishonesty were material to the cause of action so
adjudicated or (ii) that the director or officer personally gained in fact a
financial profit or other advantage to which he was not legally entitled.

         Section 6. INDEMNIFICATION OF PERSONS NOT DIRECTORS OR OFFICERS OF THE
CORPORATION.


         The Corporation may, by resolution adopted by the Board of directors of
the Corporation, indemnify any person not a director or officer of the
Corporation, who is made, or threatened to be made, a party to an action or
proceeding, whether civil or criminal, by reason of the fact that he, his
testator or intestate, is or was an employee or other agent of the Corporation,
against judgments, fines, amounts paid in settlement and expenses (including
attorneys' fees) incurred in connection with such action or proceeding, or any
appeal therein, provided that no indemnification may be made to or on behalf of
such person if (i) his acts were committed in bad faith or were the result of
active and deliberate dishonesty, and such acts were material to such action or
proceeding, or (ii) he personally gained in fact a financial profit or other
advantage to which he was not legally entitled.

         Section 7. RETROACTIVITY.

         The right to indemnification conferred by this Article V shall be
retroactive to events occurring prior to the adoption f this Article V to the
fullest extent permitted by law."

ITEM 7.       EXEMPTION FROM REGISTRATION CLAIMED

         Not applicable.

ITEM 8.       EXHIBITS

No.      Description
---      -----------

4.1      Certificate of Incorporation.*

4.2      Certificate of Amendment of the Certificate of Incorporation, Filed
         March 17, 1980.*

                                      II-4


4.3      Certificate of Amendment of the Certificate of Incorporation, Filed
         June 16, 1981.*

4.4      Certificate of Amendment to the Certificate of Incorporation, Filed
         July 22, 1988.*

4.5      Amended and Restated By-laws.*

4.6      Form of Common Stock Certificate.*

4.7      Amended and Restated Enzo Biochem, Inc. 2005 Equity Compensation
         Incentive Plan (filed as an exhibit to the Registrant's definitive
         proxy statement on Schedule 14A filed on November 28, 2005 and
         incorporated herein by reference).

4.8      Enzo Biochem, Inc. 1999 Stock Option Plan (filed as exhibit 4.1 to the
         registrant's Registration Statement on Form S-8 (Registration No.
         333-87153) and incorporated herein by reference).

4.9      Enzo Biochem, Inc. 1994 Stock Option Plan*

5.1      Legal Opinion of Greenberg Traurig, LLP.**

23.1     Consent of Ernst & Young LLP.**

23.2     Consent of Greenberg Traurig, LLP (included in exhibit 5.1).**

24.1     Powers of Attorney of the directors and certain officers of the
         registrant (included in the signature pages to the Original
         Registration Statement).*

------------------------

* Previously filed with the filing of the Original Registration Statement on
  March 31, 2005.

** Filed herewith.

ITEM 9.       UNDERTAKINGS

         (a)      The undersigned registrant hereby undertakes:

                  (1)      To file, during any period in which offers or sales
are being made, a post-effective amendment to this Registration Statement:

                  (i)      To include any prospectus required by Section
                           10(a)(3) of the Securities Act;

                  (ii)     To reflect in the prospectus any facts or events
                           arising after the effective date of this Registration
                           Statement (or the most recent post-effective
                           amendment thereof) which, individually or in the
                           aggregate, represent a fundamental change in the
                           information set forth in the Registration Statement.
                           Notwithstanding the foregoing, any increase or
                           decrease in volume of securities offered (if the
                           total dollar value of securities offered would not
                           exceed that which was registered) and any deviation
                           from the low or high end of the estimated maximum
                           offering range may be reflected in the form of
                           prospectus filed with the Commission pursuant to Rule
                           424(b) if, in the aggregate, the changes in volume
                           and price represent no more than a 20% change in the
                           maximum aggregate offering price set forth in the
                           "Calculation of Registration Fee" table in the
                           effective registration statement;

                  (iii)    To include any material information with respect to
                           the plan of distribution not previously disclosed in
                           the Registration Statement or any material change to
                           such information in the Registration Statement;

                                      II-5


                  PROVIDED, HOWEVER, that paragraphs (a)(1)(i) and (a)(1)(ii)
shall not apply to information contained in periodic reports filed by the
registrant pursuant to Section 13 or Section 15(d) of the Exchange Act that are
incorporated by reference in this Registration Statement.

                  (2)      That, for the purpose of determining any liability
under the Securities Act, each such post-effective amendment shall be deemed to
be a new registration statement relating to the securities offered therein, and
the offering of such securities at that time shall be deemed to be the initial
bona fide offering thereof.

                  (3)      To remove from registration by means of a
post-effective amendment any of the securities being registered which remain
unsold at the termination of the offering.

                  (4)      That, for the purpose of determining liability of the
registrant under the Securities Act to any purchaser in the initial distribution
of the securities, the undersigned registrant undertakes that in a primary
offering of securities of the undersigned registrant pursuant to this
Registration Statement, regardless of the underwriting method used to sell the
securities to the purchaser, if the securities are offered or sold to such
purchaser by means of any of the following communications, the undersigned
registrant will be a seller to the purchaser and will be considered to offer or
sell such securities to such purchaser:

                  (i)      Any preliminary prospectus or prospectus of the
                           undersigned registrant relating to the offering
                           required to be filed pursuant to Rule 424;

                  (ii)     Any free writing prospectus relating to the offering
                           prepared by or on behalf of the undersigned
                           registrant or used or referred to by the undersigned
                           registrant;

                  (iii)    The portion of any other free writing prospectus
                           relating to the offering containing material
                           information about the undersigned registrant or its
                           securities provided by or on behalf of the
                           undersigned registrant; and

                  (iv)     Any other communication that is an offer in the
                           offering made by the undersigned registrant to the
                           purchaser.

         (b)      The undersigned registrant hereby undertakes that, for
purposes of determining any liability under the Securities Act, each filing of
the registrant's annual report pursuant to Section 13(a) or Section 15(d) of the
Exchange Act (and, where applicable, each filing of an employee benefit plan's
annual report pursuant to Section 15(d) of the Exchange Act) that is
incorporated by reference in this Registration Statement shall be deemed to be a
new registration statement relating to the securities offered herein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

         (c)      Insofar as indemnification for liabilities arising under the
Securities Act of may be permitted to directors, officers and controlling
persons of the registrant pursuant to the foregoing provisions, or otherwise,
the registrant has been advised that in the opinion of the Securities and
Exchange Commission such indemnification is against public policy as expressed
in the Securities Act and is, therefore, unenforceable. In the event that a
claim for indemnification against such liabilities (other than the payment by
the registrant of expenses incurred or paid by a director, officer or
controlling person of the registrant in the successful defense of any action,
suit or proceeding) is asserted by such director, officer or controlling person
in connection with the securities being registered, the registrant will, unless
in the opinion of its counsel the matter has been settled by controlling
precedent, submit to a court of appropriate jurisdiction the question whether
such indemnification by it is against public policy as expressed in the
Securities Act and will be governed by the final adjudication of such issue.

                                      II-6


                                   SIGNATURES

         Pursuant to the requirements of the Securities Act of 1933, the
Registrant certifies that it has reasonable grounds to believe that it meets all
of the requirements for filing on Form S-8 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Farmingdale, New York, on April 21, 2006.



                                       ENZO BIOCHEM, INC.


                                       By:  /s/ Elazar Rabbani
                                           -------------------------------------
                                            Elazar Rabbani, Ph.D.
                                            Chairman and Chief Executive Officer


         Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed below by the following persons in the
capacities and on the dates indicated.

Date: April 21, 2006         By: /s/ Elazar Rabbani
                                -----------------------------------------
                                 Elazar Rabbani, Ph.D.
                                 Chairman of the Board of Directors and Chief
                                 Executive Officer (Principal Executive Officer)

Date: April 21, 2006         By: /s/ Shahram K. Rabbani
                                -----------------------------------------
                                 Shahram K. Rabbani
                                 Chief Operating Officer, Secretary and Director

Date: April 21, 2006         By: /s/ Barry W. Weiner
                                -----------------------------------------
                                 Barry W. Weiner
                                 President, Chief Financial Officer (Principal
                                 Financial and Accounting Officer) and Director

Date: April 21, 2006         By:     *
                                -----------------------------------------
                                 John B. Sias
                                 Director

Date: April 21, 2006         By:     *
                                -----------------------------------------
                                 John J. Delucca
                                 Director

Date: April 21, 2006         By:     *
                                -----------------------------------------
                                 Irwin C. Gerson
                                 Director

Date: April 21, 2006         By:     *
                                -----------------------------------------
                                 Melvin F. Lazar
                                 Director

Date: April 21, 2006         By:     *
                                -----------------------------------------
                                 Marcus A. Conant, M.D.
                                 Director

-------------------

*  By Elazar Rabbani, Attorney-in-Fact

                                      II-7


                                  EXHIBIT INDEX


No.               Description
---               -----------

5.1      Legal Opinion of Greenberg Traurig, LLP.

23.1     Consent of Ernst & Young LLP.