Comparison Of Assay Methods For The Detection Of Residual Protein A In Biological Therapeutics

By Peter J. Brescia and Peter Banks, BioTek Instruments, Inc., and M. Cortes-Caminero, Enzo Life Sciences

There continues to be a focus on the development of recombinant human monoclonal antibodies (rhuMAb IgGs) for therapeutic use with dozens reaching the market in the last decade. Therapeutic proteins of the scale needed for treatment of even a small population require industrial scale production using a variety of bioprocessing methods including recombinant cell line expression systems, chromatographic purification methods and stringent purity assessment. Purity requirements include minimizing the concentration of host cell proteins and DNA ranging in the parts per million or lower relative to the product. Additionally, the formulation must be sterile insuring no viable microorganisms exist in the final product and void of any residual contaminants from the purification process itself.