<PAGE>
 
                                                                   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;
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     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 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.

     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 not be sublicensed by Licensee.

     8.   Licensee shall not assign this Agreement or any part thereof without 
Licensor's prior express written consent and any attempted or purported 
assignment without such consent shall be void.  In the event Licensor grants 
such approval, then and in that event this Agreement shall be binding upon the 
parties and their respective successors and assigns.

     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 the 
quality control provisions of Paragraph 3 hereof 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 90 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.

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     the Commission. Confidential treatment has been requested with respect to
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     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 other time exception to this
paragraph 11. No non-approved labeling, marketing, advertisements or other uses
of the COLOCARE (R) will be used by Licenses 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 Sate 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> 
HELEN 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
       -------------------------            -----------------------------------
</TABLE> 


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[*]  Certain information on this page has been omitted and filed separately with
     the Commission. Confidential treatment has been requested with respect to
     the omitted portions.