Development of a high throughput protein a well-plate purification method for monoclonal antibodies

We have developed a new high throughput method for the purification of monoclonal antibodies from harvested cell culture fluid for analytical characterization. This method uses Protein A resin in a 96 well-plate format with protein loading sufficient to perform multiple analyses per well. Resin and buffer conditions were optimized to obtain aggregate and charge variant comparability with three preparative Protein A purified monoclonal antibodies. We are able to successfully demonstrate comparability for aggregate within 0.25% based upon size-exclusion chromatography. Acidic species were found to be within 2% from the preparative purified control based upon cation-exchange chromatography, 5% based upon capillary zone electrophoresis, and 3% based upon imaged capillary isoelectric focusing. Glycan distribution was analyzed and was within 1% of the preparative purified controls. A tryptic digest was performed and all peaks in the preparative purified control were found in the first elution from the well-plate format.