Patent ID: 7497950
Filing Date: 2009-03-03
Classification: C07K

Abstract:
1. A method for obtaining purified proteins, comprising: a) providing a first, a second, and a third ultrafiltration membrane with each membrane having the same, or substantially the same, molecular weight cut-off, wherein the first, second and third ultrafiltration membranes are stacked together in an unspaced arrangement and are positioned in series; b) supplying a multi-component protein mixture to the first, second and third stacked ultrafiltration membranes, the multi-component protein mixture having at least (i) a first protein and (ii) a second protein; and c) employing ultrafiltration at the first, second and third stacked ultrafiltration membranes to separate the first protein from the second protein; wherein each ultrafiltration membrane is configured to only partially reject the second protein without the other two ultrafiltration membranes being present; wherein the first, second and third stacked ultrafiltration membranes reject the second protein resulting in generation of a substantially pure first protein permeate; and wherein the operative conditions associated with the first, second and third stacked ultrafiltration membranes are controlled so as to generate the substantially pure first protein permeate.