UNITED STATES
SECURITIES AND EXCHANGE COMMISSIONWASHINGTON, D.C. 20549

FORM 10-K/A(Amendment No. 2)

|  |                                                          
|- | ---------------------------------------------------------
|x | ANNUAL
 REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE    
|  | SECURITIES
 EXCHANGE ACT OF 1934                         
|  |                                                          
|  | For
 the fiscal year ended July 31, 2009                 
|  |                                                          
|  | OR                                                       
|  |                                                          
|o | TRANSITION
 REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE
|  | SECURITIES
 EXCHANGE ACT OF 1934                         

For the transition period from ____________ to ____________

Commission file number: 001-09974

ENZO BIOCHEM, INC.(Exact name of
registrant as specified in its charter)

|                                         |  |                    
|---------------------------------------- |  | -------------------
|New York                                 |  | 13-2866202         
|(State or other jurisdiction of          |  | (I.R.S. Employer   
|incorporation or organization)           |  | Identification No.)
|                                         |  |                    
|527
 Madison Avenue
 New York, New York  |  | 10022              
|(Address of principal executive offices) |  | (Zip Code)         

Registrants telephone number, including area
code: (212) 583-0100

Securities registered pursuant to Section
12(b) of the Act:

|                                        |  |                                          
|--------------------------------------- |  | -----------------------------------------
|Title of each class                     |  | Name of each exchange on which registered
|                                        |  |                                          
|Common Stock, $0.01 par value per share |  | The New York Stock Exchange              

Securities registered pursuant to Section
12(g) of the Act: None

Indicate
by check mark if the registrant is a well-known seasoned issuer, as defined in
Rule 405 of the Securities Act.


Yes o
                    No
x


Indicate
by check mark if the registrant is not required to file reports pursuant to
Section 13 or Section 15(d) of the Exchange Act.


Yes o
                    No
x


Indicate
by check mark whether the registrant (1) has filed all reports required to be
filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the
preceding 12 months (or for such shorter period that the registrant was
required to file such reports), and (2) has been subject to such filing
requirements for the past 90 days.

Yes x
                    No
o


Indicate
by check mark whether the registrant has submitted electronically and posted on
its corporate Web site, if any, every Interactive Data File required to be
submitted and posted pursuant to Rule 405 of Regulation S-T during the
preceding 12 months (or for such shorter period that the registrant was
required to submit and post such files).

Yes o
                    No
o


Indicate by
check mark if disclosure of delinquent filers pursuant to Item 405 of
Regulation S-K is not contained herein, and will not be contained, to the best
of registrants knowledge, in definitive proxy or information statements
incorporated by reference in Part III of this Form 10-K or any amendment to
this Form 10-K.


x


Indicate
by check mark whether the registrant is a large accelerated filer, an
accelerated filer, a non-accelerated filer or a smaller reporting company. See
the definitions of large accelerated filer, accelerated filer and smaller
reporting company in Rule 12b-2 of the Exchange Act.

| |                                                                         |                             
| | ----------------------------------------------------------------------- | ----------------------------
| | Large
 accelerated filer o                                              | Accelerated
 filer x        
| |                                                                         |                             
| | Non-accelerated
 filer o
 (Do not check if a smaller reporting company) | Smaller
 reporting company o

Indicate
by check mark whether the registrant is a shell company (as defined in Rule
12b-2 of the Exchange Act).


Yes o
                    No
x


The
aggregate market value of the registrants voting stock held by non-affiliates
was approximately $166,537,000 as of January 31, 2009.

The
number of shares of the registrants common stock, par value $.01, outstanding
as of December 1, 2009 was approximately 37,858,000.

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EXPLANATORY NOTE

Enzo
Biochem, Inc. (the Company) is filing this Amendment No. 2 to its Annual
Report on Form 10-K for the fiscal year ended July 31, 2009, filed with the
Securities and Exchange Commission on October 14, 2009, as amended by Amendment
No. 1, filed with the Securities and Exchange Commission on November 25, 2009,
solely for the purpose of making certain technical reference corrections in the
exhibit index. In connection with the filing of this Amendment, and as required
by Rule 12b-15 of the Securities Exchange Act of 1934 (the Exchange Act), the
Company is also filing new certifications of its principal executive officer
and principal financial officer pursuant to Rule 13a-14(a)/15d-14(a) of the
Exchange Act.

Unless
otherwise stated, this Amendment No. 2 does not reflect events occurring after
the filing of the original Form 10-K or modify or update in any way disclosures
contained in the original Form 10-K.

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TABLE OF CONTENTS

|PART IV                                          | 1
|------------------------------------------------ | -
|Item 15. Exhibits, Financial Statement Schedules | 1
|SIGNATURES                                       | 3
|EX 31(e)                                         |  
|EX 31(f)                                         |  

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PART IV

Item 15. Exhibits and Financial Statements
Schedules

a) Documents
filed as part of the report

(3) Exhibits.

|              |  |                                                                                                                                                                                                                             
|------------- |  | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|Exhibit 
 No. |  | Description                                                                                                                                                                                                                 
|              |  |                                                                                                                                                                                                                             
|              |  |                                                                                                                                                                                                                             
|3(a)          |  | Certificate
 of Incorporation, as amended March 17, 1980. (1)                                                                                                                                                               
|              |  |                                                                                                                                                                                                                             
|3(b)          |  | June 16,
 1981 Certificate of Amendment of the Certificate of Incorporation. (2)                                                                                                                                            
|              |  |                                                                                                                                                                                                                             
|3(c)          |  | Certificate
 of Amendment to the Certificate of Incorporation. (3)                                                                                                                                                          
|              |  |                                                                                                                                                                                                                             
|3(d)          |  | Amended and
 restated Bylaws. (4)                                                                                                                                                                                           
|              |  |                                                                                                                                                                                                                             
|10 (c)        |  | Employment
 Agreements with Elazar Rabbani. (5)                                                                                                                                                                             
|              |  |                                                                                                                                                                                                                             
|10(d)         |  | Employment
 Agreement with Shahram Rabbani. (5)                                                                                                                                                                             
|              |  |                                                                                                                                                                                                                             
|10(e)         |  | Employment
 Agreement with Barry Weiner. (5)                                                                                                                                                                                
|              |  |                                                                                                                                                                                                                             
|10(f)         |  | 1994 Stock
 Option Plan. (6)                                                                                                                                                                                                
|              |  |                                                                                                                                                                                                                             
|10(g)         |  | 1999 Stock
 Option Plan. (7)                                                                                                                                                                                                
|              |  |                                                                                                                                                                                                                             
|10 (h)        |  | Amendment to
 Elazar Rabbanis employment agreement. (8)                                                                                                                                                                    
|              |  |                                                                                                                                                                                                                             
|10 (i)        |  | Amendment to
 Shahram Rabbanis employment agreement. (8)                                                                                                                                                                   
|              |  |                                                                                                                                                                                                                             
|10 (j)        |  | Amendment to
 Barry Weiners employment agreement. (8)                                                                                                                                                                      
|              |  |                                                                                                                                                                                                                             
|10 (k)        |  | 2005 Equity
 Compensation Incentive Plan. (9)                                                                                                                                                                               
|              |  |                                                                                                                                                                                                                             
|10 (l)        |  | Amended and
 Restated Lease Agreement with Pari Management. (10)                                                                                                                                                            
|              |  |                                                                                                                                                                                                                             
|10 (m)        |  | Settlement
 and Release Agreement between the Company and Sigma Aldrich. (11)                                                                                                                                               
|              |  |                                                                                                                                                                                                                             
|10 (n)        |  | Stock
 Purchase Agreement by and among Enzo Life Sciences, Inc., Axxora Life
 Sciences Inc., and the stock holders, option holders and warrant holders
 listed on Schedule I thereto. (12)                                  
|              |  |                                                                                                                                                                                                                             
|10 (o)        |  | Stock Asset
 Purchase Agreement By and Among Buyer Parties and Seller Parties. (13)                                                                                                                                         
|              |  |                                                                                                                                                                                                                             
|10 (p)        |  | Asset
 Purchase Agreement By and Among Enzo Life Sciences, Inc., Enzo Life Sciences
 Acquisition, Inc., Assay Designs, Inc., Ampersand 2001 Limited Partnership
 and Ampersand 2001 Companion Fund Limited Partnership. (14)
|              |  |                                                                                                                                                                                                                             
|14 (a)        |  | Code of
 Ethics. (15)                                                                                                                                                                                                       
|              |  |                                                                                                                                                                                                                             
|21            |  | Subsidiaries
 of the registrant:                                                                                                                                                                                            
|              |  |                                                                                                                                                                                                                             
|              |  | Enzo
 Clinical Labs, Inc., a New York corporation                                                                                                                                                                           
|              |  | Enzo Life
 Sciences, Inc., a New York corporation                                                                                                                                                                           
|              |  | Enzo
 Therapeutics, Inc., a New York corporation                                                                                                                                                                            
|              |  | Enzo Realty,
 LLC, a New York corporation                                                                                                                                                                                   

1

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|       |  |                                                                                                                                                                      
|------ |  | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------
|23     |  | Consent of
 Independent Registered Public Accounting Firm. (16)                                                                                                      
|       |  |                                                                                                                                                                      
|31 (a) |  | Certification
 of CEO Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002. (16)                                                                                
|       |  |                                                                                                                                                                      
|31 (b) |  | Certification
 of CFO Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002. (16)                                                                                
|       |  |                                                                                                                                                                      
|31 (c) |  | Certification
 of CEO Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002. (17)                                                                                
|       |  |                                                                                                                                                                      
|31 (d) |  | Certification
 of CFO Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002. (17)                                                                                
|       |  |                                                                                                                                                                      
|31(e)  |  | Certification
 of CEO Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002 filed
 herewith.                                                                     
|       |  |                                                                                                                                                                      
|31(f)  |  | Certification
 of CFO Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002 filed
 herewith.                                                                     
|       |  |                                                                                                                                                                      
|32 (a) |  | Certification
 of CEO Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002. (16)                                                                                
|       |  |                                                                                                                                                                      
|32 (b) |  | Certification
 of CFO Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002. (16)                                                                                
|       |  |                                                                                                                                                                      
|       |  | Notes to exhibits                                                                                                                                                    
|       |  |                                                                                                                                                                      
|(1)    |  | These
 exhibits were filed as exhibits to the Companys Registration Statement on
 Form S-18 (File No. 2-67359) and are incorporated herein by reference.            
|       |  |                                                                                                                                                                      
|(2)    |  | This exhibit
 was filed as an exhibit to the Companys Form 10-K for the year ended July
 31, 1981 and is incorporated herein by reference.                          
|       |  |                                                                                                                                                                      
|(3)    |  | This exhibit
 was filed with the Companys Annual Report on Form 10-K for the year ended
 July 31, 1989 and is incorporated herein by reference.                     
|       |  |                                                                                                                                                                      
|(4)    |  | This exhibit
 was filed with Amendment No. 1 to the Companys Current Report on Form 8-K on
 January 30, 2008 and is incorporated herein by reference.               
|       |  |                                                                                                                                                                      
|(5)    |  | This exhibit
 was filed with the Companys Annual Report on Form 10-K for the year ended
 July 31, 1994 and is incorporated herein by reference.                     
|       |  |                                                                                                                                                                      
|(6)    |  | This exhibit
 was filed with the Companys Annual Report on Form 10-K for the year ended
 July 31, 1995 and is incorporated herein by reference.                     
|       |  |                                                                                                                                                                      
|(7)    |  | This exhibit
 was filed with the Companys Registration Statement on Form S-8 (333-87153)
 and is incorporated herein by reference.                                  
|       |  |                                                                                                                                                                      
|(8)    |  | This exhibit
 was filed with the Companys Annual Report on Form 10-K for the year ended
 July 31, 2000 and is incorporated herein by reference.                     
|       |  |                                                                                                                                                                      
|(9)    |  | This exhibit
 was included in the Companys Proxy Statement on Schedule 14A filed on
 January 19, 2005 and is incorporated herein by reference.                      
|       |  |                                                                                                                                                                      
|(10)   |  | This exhibit
 was filed with the Companys Annual Report on Form 10-K for the year ended
 July 31, 2005 and is incorporated herein by reference.                     
|       |  |                                                                                                                                                                      
|(11)   |  | This exhibit
 was filed with the Companys Current Report on Form 8-K on September 21, 2006
 and is incorporated herein by reference.                                
|       |  |                                                                                                                                                                      
|(12)   |  | This exhibit
 was filed with the Companys Current Report on Form 8-K on May 30, 2007 and
 is incorporated herein by reference.                                      
|       |  |                                                                                                                                                                      
|(13)   |  | This exhibit
 was filed with the Companys Current Report on Form 8-K on May 9, 2008 and is
 incorporated herein by reference.                                       
|       |  |                                                                                                                                                                      
|(14)   |  | This exhibit
 was filed with the Companys Current Report on Form 8-K on March 13, 2009 and
 is incorporated herein by reference.                                    
|       |  |                                                                                                                                                                      
|(15)   |  | This exhibit
 was filed with the Companys Annual Report on Form 10-K for the year ended
 July 31, 2003 and is incorporated herein by reference.                     
|       |  |                                                                                                                                                                      
|(16)   |  | This exhibit
 was filed with the Companys Annual Report on Form 10-K for the year ended
 July 31, 2009 and is incorporated herein by reference.                     
|       |  |                                                                                                                                                                      
|(17)   |  | This exhibit
 was filed with Amendment No. 1 to the Companys Annual Report on Form 10-K/A
 for the year ended July 31, 2009 and is incorporated herein by reference.

2

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SIGNATURES

Pursuant
to the requirements of Section 13 or 15(d) of the Securities Exchange Act
of 1934, the Registrant has duly caused this amendment to the Annual Report on
Form 10-K to be signed on its behalf by the undersigned, thereunto duly authorized
on the 11th day of December, 2009.

| |                    |        |                                                                            
| | ------------------ | ------ | ---------------------------------------------------------------------------
| | ENZO BIOCHEM, INC.
| |                   
| | By:                |        | /s/ Elazar Rabbani                                                         
| |                    |       
| |                    | Name:  | Elazar Rabbani Ph.D.                                                       
| |                    | Title: | Chairman of
 the Board of Directors,
 Secretary and Chief Executive Officer

3

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