The invention herein provides a method for recovering a polypeptide comprising exposing a composition comprising a polypeptide to a reagent which binds to, or modifies, the polypeptide, wherein the reagent is immobilized on a solid phase; and then passing the composition through a filter bearing a charge which is opposite to the charge of the reagent in the composition, so as to remove leached reagent from the composition.
RELATED APPLICATIONS
This is a continuation application claiming priority under 35 USC .sctn.120 to application Ser. No. 09/460,587, filed Dec. 14, 1999, now U.S. Pat. No. 6,322,997, which is a divisional of application Ser. No. 09/097,309, filed Jun. 12, 1998, now U.S. Pat. No. 6,121,428, which claims the benefit under 35 USC .sctn.119(e) to provisional application number 60/050,951 filed Jun. 13, 1997, the disclosures of which are hereby incorporated by reference.
