EXHIBIT 31.1

                           APPLIED DNA SCIENCES, INC.
                  OFFICER'S CERTIFICATE PURSUANT TO SECTION 302

I,   Peter Brocklesby,  the President  (Principal  Executive Officer) of Applied
     DNA Sciences, Inc., certify that:

1.   I have  reviewed  this  quarterly  report  on Form  10-QSB of  Applied  DNA
     Sciences, Inc.;

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 quarterly report;

3.   Based on my  knowledge,  the  financial  statements,  and  other  financial
     information  included  in this  quarterly  report,  fairly  present  in all
     material respects the financial  condition,  results of operations and cash
     flows of the Small Business Issuer as of, and for, the periods presented in
     this quarterly report;

4.   The Small Business Issuer's other certifying officers 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 Small Business Issuer 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 small
          business  issuer,  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;

     (b)  [Omitted pursuant to SEC Release No. 33-8238];

     (c)  Evaluated the effectiveness of the Small Business Issuer'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 Small  Business  Issuer's
          internal  control over financial  reporting  that occurred  during the
          small business issuer's most recent fiscal quarter (the small business
          issuer's  fourth fiscal  quarter in the case of an annual report) that
          has materially affected, or is reasonably likely to materially affect,
          the small business issuer's internal control over financial reporting;
          and

5.   The  Small  Business  Issuer's  other  certifying  officer(s)  and  I  have
     disclosed,  based on our most recent  evaluation  of internal  control over
     financial  reporting,  to the small business issuer's auditors of the small
     business issuer's board of directors (or persons  performing the equivalent
     functions):

     (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 small  business  issuer's
          ability   to  record,   process,   summarize   and  report   financial
          information; and

     (b)  Any fraud, whether or not material,  that involves management or other
          employees who have a significant  role in the small business  issuer's
          internal control over financial reporting.

Date:     August 3, 2005

/s/ PETER BROCKLESBY
-----------------
Peter Brocklesby
President
(Principal Executive Officer)