Protein A chromatography: Challenges and progress in the purification of monoclonal antibodies.

Antibodies for therapeutic use are being continuously approved and their demand has been steadily growing. As known, the golden standard for monoclonal antibody (mAb) purification is Protein A affinity chromatography, a technology that has gained high interest because of its great performance and capabilities. The main concerns are the elevated resins costs and their limited lifetime compared to other resins (e.g. ion exchange chromatography). Great efforts have been carried out to improve purification conditions, such as resin characterization and designing alkali/acid stable resins with a longer lifetime. Modification of Protein A ligands and alternative formats such as monoliths membranes and microshperes have been tested to increase the purification performance. New technology has been proposed to improve the large-scale separation; in addition, alternative ligands have been suggested to capture mAbs instead of Protein A ligand; however, most of the information is locked by pharmaceutical companies. This mini review summarizes and describes the advances, results, and impact on the Protein A chromatography purification processing.