Abstract: Herein is reported a method for the purification or production of a therapeutic polypeptide using the same depth filter multiple times, i.e. a depth filter which has been used before and has been regenerated. Reported herein is a method for purifying or producing a therapeutic polypeptide, characterized in that the method comprises the following steps: a) filtering an aqueous composition containing said therapeutic polypeptide and impurities through a depth filter, recovering the flow-through and thereby obtaining said purified therapeutic polypeptide, b) contacting said depth filter with a regeneration solution and thereby regenerating the depth filter, and c) repeating steps a) and b) one or more times.

Abstract: The invention relates to a method of reducing the amount of non-aggregate produce-related impurities (NAPRIs) in a buffered solution of monoclonal antibodies (mAbs), involving the use of a synthetic depth filter. The invention may be of use in the purification of monoclonal 5 antibodies.