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Exhibit 31.1

Certifications

I, William G. Gerber, President and Chief Executive Officer of Epoch
Biosciences, Inc. (the Company), certify that:



|1. |  | I have reviewed this quarterly report on Form 10-Q of the Company;                                                                                                                                                                                                                                                  
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|2. |  | Based on my knowledge, this quarterly 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;
|  
|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;                             
|  
|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) for the registrant
and have:                                                                                          



| |  | 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) [Paragraph omitted pursuant to SEC Release Nos. 33-8238 and 34-47986]                                                                                                                                                                                                                                                                                                                  
|
| |  | 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                                                                                                    
|
| |  | 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 (the registrants fourth fiscal quarter in the
case of an annual report) that has materially affected, or is reasonably
likely to materially affect, the registrants internal control over
financial reporting; and



|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 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
controls over financial reporting.                                                                                              

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|Date: |  | August 6, 2003 |  | By: |  | /s/ William G. Gerber                
|      |  |                |  |     |  |                                      
|      |  |                |  |     |  | William G. Gerber                    
|      |  |                |  |     |  | President and Chief Executive Officer