EXTENSION OF EMPLOYMENT AGREEMENT DATE: March 31, 1999 PARTIES: Techne Corporation, a Minnesota corporation 614 McKinley Place N.E. Minneapolis, Minnesota 55413 Monica Tsang, Ph.D. AGREEMENTS: The parties hereby agree that the termination date of the...

                    EXTENSION OF EMPLOYMENT AGREEMENT


DATE:      March 31, 1999

PARTIES:   Techne Corporation, a
           Minnesota corporation
           000 XxXxxxxx Xxxxx X.X.
           Xxxxxxxxxxx, Xxxxxxxxx  00000

           Xxxxxx Xxxxx, Ph.D.


AGREEMENTS:

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


                                        TECHNE CORPORATION



                                  By      /s/ Xxxxxx X. Xxxxx 
                                          -------------------------------		
                                          Xxxxxx X. Xxxxx, President
                                          "Company"


                                          /s/ Xxxxxx Xxxxx         
                                          ------------------------------ 
                                          Xxxxxx Xxxxx, Ph.D.
                                          "Employee"