EXTENSION OF EMPLOYMENT AGREEMENT DATE: March 31, 1999 PARTIES: Techne Corporation, a Minnesota corporation 614 McKinley Place N.E. Minneapolis, Minnesota 55413 Thomas C. Detwiler, Ph.D. 1601 Northrap Lane Minneapolis, Minnesota 55403 AGREEMENTS: The...

                    EXTENSION OF EMPLOYMENT AGREEMENT


DATE:           March 31, 1999

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

                Xxxxxx X. Xxxxxxxx, Ph.D.
                0000 Xxxxxxxx Xxxx
                Xxxxxxxxxxx, Xxxxxxxxx  00000


AGREEMENTS:

	The parties hereby agree that the termination date of the Employment
Agreement between them dated December 28, 1995 and 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 X. Xxxxxxxx
                                          -------------------------------       
                                          Xxxxxx X. Xxxxxxxx, Ph.D.
                                          "Employee"