Exhibit 3.5

 
     CERTIFICATE OF CORRECTION FILED TO CORRECT A CERTAIN ERROR IN THE
     CERTIFICATE TO SET FORTH DESIGNATIONS, VOTING POWERS, PREFERENCES,
     LIMITATIONS, RESTRICTIONS, AND RELATIVE RIGHTS OF SERIES A 6% CUMULATIVE
     CONVERTIBLE PREFERRED STOCK, $0.001 PAR VALUE PER SHARE OF CHEMTRAK
     INCORPORATED FILED IN THE OFFICE OF THE SECRETARY OF STATE OF DELAWARE ON
     JANUARY 16, 1998

CHEMTRAK INCORPORATED hereby certifies that:

     1.   The name of the corporation is ChemTrak Incorporated, a Delaware
corporation.

     2.   That a CERTIFICATE TO SET FORTH DESIGNATIONS, VOTING POWERS,
PREFERENCES, LIMITATIONS, RESTRICTIONS, AND RELATIVE RIGHTS OF SERIES A 6%
CUMULATIVE CONVERTIBLE PREFERRED STOCK, $0.001 PAR VALUE PER SHARE was filed by
the Secretary of State of Delaware on January 16, 1998 and that said Certificate
requires correction as permitted under Section 103 of the General Corporation
Law of the State of Delaware.

       3.      The inaccuracy or defect of said Certificate to be corrected is
as follows:  Article II, Section 5(f) included a clerical error.

     4.   Article II, Section 5(f) of the Certificate is corrected to read as
follows:
 
               (f) Subject to the provisions of this section, if the Corporation
     at any time shall issue any shares of Common Stock prior to the conversion
     of the entire Stated Value of the Series A Preferred Stock (otherwise than
     as: (i) provided in paragraphs (d) and (e) of this paragraph 4; or (ii)
     pursuant to options, warrants, or other obligations to issue shares,
     outstanding on the date hereof as described in public filings made by the
     Corporation prior to the date hereof with the Securities and Exchange
     Commission including all shares reserved for issuance pursuant to the
     Corporation's existing option and stock plans ((i) and (ii) above, are
     hereinafter referred to as the "Existing Option Obligations") for a
     consideration less than the Conversion Price that would be in effect at the
     time of such issue, then, and thereafter successively upon each such issue,
     the Conversion Price shall be reduced as follows: (i) the number of shares
     of Common Stock outstanding immediately prior to such issue shall be
     multiplied by the Conversion Price in effect at the time of such issue and
     the product shall be added to the aggregate consideration, if any, received
     by the Corporation upon such issue of additional shares of Common Stock;
     and (ii) the sum so obtained shall be divided by the number of shares of
     Common Stock outstanding immediately after such issue.  Except for the
     Existing Option Obligations and options that may be issued under any
     employee incentive stock option and/or any qualified 

 
     stock option plan adopted by the Company, for purposes of this
     adjustment, the issuance of any security of the Corporation carrying the
     right to convert such security into shares of Common Stock or of any
     warrant, right or option to purchase Common Stock shall result in an
     adjustment to the Conversion Price upon the issuance of shares of Common
     Stock upon exercise of such conversion or purchase rights.

     IN WITNESS WHEREOF, said CHEMTRAK INCORPORATED has caused this Certificate
to be signed by Edward Covell, its President, and attested by Donald Fluken, its
Chief Financial Officer, this 20th day of January, 1998.

     Signed on this 20th day of January, 1998.

                              CHEMTRAK, INCORPORATED



                              By:/s/ Edward F. Covell
                                 ----------------------------------------------
                                     President


ATTEST:


/s/ Donald V. Fluken
- -------------------------------------------------
Chief Financial Officer


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