Development of a multi-product leached protein A assay for bioprocess samples containing recombinant human monoclonal antibodies.

The detection of low level of protein A leached from monoclonal antibody downstream purification process is often interfered by the presence of excess amount of product antibody. In order to prevent this interference, we developed a new multi-product leached protein A assay that used acidification to completely dissociate the IgG-ProteinA complex, followed by neutralization under selected condition to prevent re-formation of the IgG-ProteinA complex. The amount of protein A was then determined by a sandwich immunoassay using Meso Scale Discovery technology.

Using precipitation by polyamines as an alternative to chromatographic separation in antibody purification processes.

Polyamine precipitation conditions for removing host cell protein impurities from the cell culture fluid containing monoclonal antibody were studied. We examined the impact of polyamine concentration, size, structure, cell culture fluid pH and ionic strength. A 96-well microtiter plate based high throughput screening method was developed and used for evaluating different polyamines.

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.