EXHIBIT 31.1

CERTIFICATION PURSUANT TOSECTION 302 OF THE SARBANES-OXLEY ACT OF 2002

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|I, Elazar Rabbani,
 Ph.D., certify that:
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|1.                                       | I have reviewed
 this quarterly report on Form 10-Q of Enzo Biochem, Inc (the registrant).                                                                                                                                                                                                                                                 
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|2.                                       | Based on my
 knowledge, this report does not contain any untrue statement of a material
 fact or omit to state a material fact necessary to make the statements made,
 in light of the circumstances under which such statements were made, not
 misleading with respect to the period covered by this report;                               
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|3.                                       | Based on my
 knowledge, the financial statements, and other financial information included
 in this report, fairly present in all material respects the financial
 condition, results of operations and cash flows of the registrant as of, and
 for, the periods presented in this report;                                                  
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|4.                                       | The registrants
 other certifying officer and I are responsible for establishing and
 maintaining disclosure controls and procedures (as defined in Exchange Act
 Rules 13a  15(e) and 15d  15(e)) and internal control over financial
 reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the
 registrant and have:
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|                                         | (a)                                                                                                                                                                                                                                                                                                                                           | Designed such
 disclosure controls and procedures, or caused such disclosure controls and
 procedures to be designed under our supervision, to ensure that material
 information relating to the registrant, including its consolidated
 subsidiaries, is made known to us by others within those entities,
 particularly during the period in which this report is being prepared;
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|                                         | (b)                                                                                                                                                                                                                                                                                                                                           | Designed such
 internal control over financial reporting, or caused such internal control
 over financial reporting to be designed under our supervision, to provide
 reasonable assurance regarding the reliability of financial reporting and the
 preparation of financial statements for external purposes in accordance with
 generally accepted accounting principles;       
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|                                         | (c)                                                                                                                                                                                                                                                                                                                                           | Evaluated the
 effectiveness of the registrants disclosure controls and procedures and
 presented in this report our conclusions about the effectiveness of the
 disclosure controls and procedures, as of the end of the period covered by
 this report based on such evaluation; and                                                                                            
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|                                         | (d)                                                                                                                                                                                                                                                                                                                                           | Disclosed in this
 report any change in the registrants internal control over financial
 reporting that occurred during the registrants most recent fiscal quarter
 that has materially affected, or is reasonably likely to materially affect,
 the registrants internal control over financial reporting; and                                                                 
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|5.                                       | The registrants
 other certifying officer and I have disclosed, based on our most recent
 evaluation of internal control over financial reporting, to the registrants
 auditors and the audit committee of the registrants board of directors (or
 persons performing the equivalent functions):                                          
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|                                         | (a)                                                                                                                                                                                                                                                                                                                                           | All significant
 deficiencies and material weaknesses in the design or operation of internal
 control over financial reporting which are reasonably likely to adversely
 affect the registrants ability to record, process, summarize and report
 financial information; and                                                                                                      
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|                                         | (b)                                                                                                                                                                                                                                                                                                                                           | Any fraud, whether
 or not material, that involves management or other employees who have a
 significant role in the registrants internal control over financial
 reporting.                                                                                                                                                                                                      

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|------------------------ | --- | -------------------------------------------------------------
|Date: December 10,
 2009 |     |                                                              
|                         | By: | /s/ Elazar
 Rabbani, Ph.D.                                   
|                         |     |                                                              
|                         |     | Elazar Rabbani,
 Ph.D.                                       
|                         |     | Chairman of the
 Board, Chief Executive Officer and Secretary

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