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

Claim 0:
1. 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 sufficiently distinct from the pI of the polypeptide to enhance the charge of the polypeptide and a low ionic strength effective to prevent the shielding of charges by buffer ions, 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 step, and
e. recovering the purified polypeptide from the effluent of the cation exchange chromatography step.