Simple, environmentally benign, method for purifying protein A

Abstract

High purity protein A is recovered from protein A preparations by passing a protein A preparation over an ion exchange column so that protein A will bind to a cation exchange resin. The loaded column is washed with a wash buffer solution having about the same pH as the protein A preparation and an increased mineral salt concentration to elute certain impurities but not the protein A. The protein A is eluted from the washed column by eluting the column with an elution buffer solution having a pH higher than the wash buffer solution and mineral salt concentration substantially no higher than the wash buffer solution. The protein A can be easily recovered from protein A preparations that do not use any human or animal components. The protein A purified by the invention is suitable for all common uses of protein A, but is especially well-suited for human therapeutic applications.

Dependencies are inferred from the claim text.