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                                                                   EXHIBIT 10.39


                       LICENSE AND DISTRIBUTION AGREEMENT


        THIS AGREEMENT (the "Agreement") is made between Helena Laboratories
Corporation (hereinafter referred to as "Licensor") located at 1530 Lindbergh
Drive, Beaumont, Texas 77704-0752 and ChemTrak Inc. (hereinafter referred to as
"Licensee") located at 929 East Arques Avenue, Sunnyvale, California
94086-4520.

         WHEREAS, Licensor is the owner of all right, title and interest in and
to the trademark COLOCARE(R) as shown in U.S. Trademark Registration No.
1,651,398 issued July 23, 1991, has used that trademark and established
substantial goodwill associated therewith; and

         WHEREAS, Licensee desires to distribute Colocare brand products under
license from Licensor; and

         WHEREAS, Licensor is willing to provide Colocare brand products under
license to Licensee under specific terms and conditions; and

         WHEREAS, Licensee and Licensor are desirous of formalizing an
agreement;

        
         IT IS HEREBY AGREED AS FOLLOWS:

         1.      Licensor grants to Licensee a non-exclusive license to use its
trademark COLOCARE(R) solely in conjunction with distribution of a test for
fecal occult blood manufactured by Licensor, in the retail, over-the-counter
market in the United States.  Licensee agrees that any other use of the
trademark COLOCARE(R), and any other distribution of a fecal occult blood text
product in connection with the trademark COLOCARE(R), is expressly prohibited
under this Agreement.  By way of example and not by way of limitation, any use
of the trademark COLOCARE(R), and any distribution of a fecal occult blood test
product in connection with the trademark COLOCARE(R), in the U.S. professional
market and/or in any non-U.S. markets is expressly prohibited by this
Agreement.

         2.      All use of the COLOCARE(R) trademark by Licensee, shall inure
to the benefit of Licensor.

         3.      In consideration of the license granted hereunder, Licensee
agrees that it shall only use the COLOCARE(R) trademark on goods manufactured
by Licensor and supplied to Licensee by Licensor, thereby assuring that the
quality of the goods meets Licensor's standards.





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         4.      The parties agree that (a) Licensee shall order COLOCARE(R)
brand fecal occult blood test products in [                ] lots; (b) the
price per test unit shall be [     ], (c) no order shall be placed for less
than [                 ] at a time; and (d) the test unit shall include one
fecal occult blood test (3 individual pads per test unit) in one foil pouch
with one printed instruction sheet.

         5.      Licensee agrees that during the term of this Agreement it will
not develop, contract to develop, manufacture, sell, license, lease, or
otherwise distribute any product which is directly competitive with the
COLOCARE(R) brand fecal occult blood test product.

         6.      Licensee shall not do, or permit to be done, anything that may
tend to jeopardize the validity of, or diminish the value of the licensed
trademark.

         7.      The licensed trademark shall [                   ] by Licensee.

         8.      Licensee shall not [            ], or [                    ], 
without Licensor's [                  ], and [                              ].  
In the event Licensor [                              ], then and in that event
this Agreement [                    ] and [                             ].

         9.      Licensee shall hold Licensor and its agents harmless and
indemnify Licensor from and against all claims, charges, damages and
liabilities of all kinds, including reasonable attorneys' fees and losses to
intangibles such as, but not limited to, trademark value and good will,
incurred as a result of the breach by licensee of any provision contained in
this Agreement.

         10.     This Agreement is effective from the date of execution until
February 28, 1999.  The Agreement may be renewed for successive one-year
periods provided both parties agree to such a renewal, in writing, in advance.

        11.     Licensor shall have the right to terminate the license
agreement at any time in the event that Licensee is in default in the
performance of any covenant contained in this Agreement.  Grounds for such
termination shall include, but not be limited to, the failure of Licensee to
comply with [                                                    ], or
abandonment of the mark by Licensee.  Such termination shall be effected by
notice to Licensee specifying the grounds for termination and the date for
termination, which date shall not be less than [  ] days after the giving of
such notice.  Such termination shall not become effective, however, if the
specified grounds for termination are cured on or before the specified date of
termination.  In no event shall any money paid by Licensee to Licensor under
the terms of this agreement be refunded to Licensee upon termination of this
Agreement.

         12.     Licensor shall review and approve all labeling, marketing,
 advertisements and other uses of the COLOCARE(R) trademark [ ] for product
 accuracy and for proper trademark usage.  Licensee shall always use the
 symbol (R) in connection with the term "colocare" except that Licensee's
 initial printing of COLOCARE(TM) is hereby approved as a one-




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time exception to this paragraph 11.  No non-approved labeling, marketing,
advertisements or other uses of the COLOCARE(R) will be used by Licensee and
any non-approved use shall be considered non-licensed.

      13.     While the Agreement is non-exclusive, in the event that Licensor 
 [                   ], Licensor shall [               ] and [              ].  
 In the event Licensee [             ], then such [                         ].

         14.     This Agreement shall be interpreted under the laws of the
State of Texas except that matters of federal trademark law shall be
interpreted under federal law.  In the event that any portion of this Agreement
should be determined to be void or invalid or unenforceable for any reason, the
remaining terms shall be interpreted so as to reflect the basic intentions and
intentions and objectives of the parties.

         15.     The Licensor and Licensee agree that the terms of this
Agreement shall not be the subject of any public announcement and shall not be
disclosed, except as required by statute, regulation or order of court.

         IN WITNESS WHEREOF, the parties have caused this Agreement to be
executed by their duly authorized representatives.

<TABLE>
<S>                                        <C>    
HELENA LABORATORIES CORPORATION            CHEMTRAK INC.


Date:    2/27/97                           Date:    2/27/97
       ----------------------------              --------------------------------------

By:      /s/ Eric Petersen                 By:      /s/ Edward F. Covell
       ----------------------------              --------------------------------------

Name:    Eric Petersen                     Name:    Edward F. Covell               
       ----------------------------              --------------------------------------

Title:   Vice President                    Title:   President/Chief Executive Officer
       ----------------------------              --------------------------------------
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