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                                                                EXHIBIT 10.21

                               WAIVER AND RELEASE

        The undersigned, CHARLES GELMAN and KIM A. DAVIS, with the intent of
binding themselves and their representatives, successors and assigns, execute
this Waiver and Release in favor of each other and Gelman Sciences, Inc.
("Company"). 

        In consideration for amendments dated as of May 1, 1996 to their
respective employment agreements dated August 1, 1995 and other good and
valuable considerations, the receipt and sufficiency of which are hereby
acknowledged, the undersigned, CHARLES GELMAN and KIM A. DAVIS, each, on behalf
of themselves and their respective successors and assigns, hereby waive,
release and forever discharge each other, their respective successors and
assigns, the Company, and all of its officers, directors, employees, successors
and assigns from any and all claims, charges, debts, dues, liabilities and
damages which either of them may have against any of such parties arising prior
to May 1, 1996, excluding only the liabilities and obligations which the
Company owes to each of the undersigned under their respective employment
agreements dated August 1, 1995, as amended.

        The undersigned have read this Waiver and Release, understand all of
its terms, and execute it voluntarily and with full knowledge of its
significance. 

        IN WITNESS WHEREOF, the undersigned execute this Release at Ann Arbor,
Michigan on May 1, 1996.

WITNESSES:

John A. Geishecker, Jr.                         /s/ Charles Gelman
- --------------------------                      -------------------------
                                                /s/ Charles Gelman

                                                /s/ Kim A. Davis
- --------------------------                      -------------------------
                                                    Kim A. Davis


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