Patent ID: 10112971

Abstract:
A method of purifying a desired protein from a preparation includes (a) providing the preparation in a form having less than about 5% of chromatin residing in an original production medium, (b) contacting the preparation with a nonionic organic polymer and a salt, a concentration of nonionic organic polymer being sufficient to precipitate the desired protein or cause its accretion on a hydrophilic surface, or maintain it in a precipitated state or accreted on the hydrophilic surface, the salt concentration being sufficient to produce greater than physiological conductivity, and (c) contacting the preparation with at least one electropositive surface, optionally in the presence of a salt concentration sufficient to produce greater than physiological conductivity, the desired protein does not substantially adsorb to the at least one electropositive surface while not preventing adsorption of acidic contaminants to the at least one electropositive surface.