Patent ID: 11945837
Assignee: GENENTECH, INC.
Field: Biotechnology (Chemistry)
Classification: CPC C | IPC B  C

Claim 13:
14. A method of enhancing efficiency of downstream chromatography steps for purification of proteins comprising:
a. passing a composition comprising a polypeptide of interest and one or more contaminants through a cation exchange membrane, wherein the one or more contaminants is one or more of a host cell protein, aminoglycoside antibiotic, nucleic acid, a variant of the polypeptide of interest, another polypeptide, an endotoxin, or a viral contaminant, wherein the polypeptide and the membrane have opposite charge, at operating conditions comprised of a buffer having a pH of about 1 to about 5 pH units below the pI of the polypeptide and a conductivity of < about 40 mS/cm, which cause the membrane to bind the polypeptide and at least one contaminant,
b. overloading the cation exchange membrane such that at least one contaminant remains bound to the membrane while the polypeptide of interest is primarily in the effluent;
c. collecting the effluent from the cation exchange membrane comprising the polypeptide of interest;
d. subjecting the membrane effluent comprising the polypeptide of interest to a cation exchange chromatography purification step, and
e. recovering the purified polypeptide from the effluent of the cation exchange chromatography purification step.