EXTENSION OF EMPLOYMENT AGREEMENT DATE: August 28, 2001 Parties: Techne Corporation 614 McKinley Place N.E. Minneapolis, MN 55413 Monica Tsang, Ph.D. AGREEMENTS: The parties hereby agree that the termination date of the Employment Agreement between...

                    EXTENSION OF EMPLOYMENT AGREEMENT


DATE:      August 28, 2001

Parties:   Techne Corporation
           000 XxXxxxxx Xxxxx X.X.
           Xxxxxxxxxxx, XX  00000


           Xxxxxx Xxxxx, Ph.D.


AGREEMENTS:

     The parties hereby agree that the termination date of the Employment
Agreement between them for the period July 1, 1995 through June 30, 1998 and
previously extended to June 30, 2001 is extended to June 30, 2004.  All other
provisions of such Employment Agreement shall remain in full force and
effect.


                                             Techne Corporation


                                             By /s/ Xxxxxx X. Xxxxx
                                                Xxxxxx X. Xxxxx, President


                                                /s/ Xxxxxx Xxxxx
                                                Xxxxxx Xxxxx, Ph.D.