A novel rProtein A chromatographic media for enhancing cleaning-in-place performance.

Protein A chromatography has been a popular method for purification of therapeutic monoclonal antibodies (mAb). Protein A chromatographic media using alkali-resistant rProtein A ligands from site-directed coupling method have been pursued for both high dynamic capacities and excellent stabilities. However, the mechanism of rProtein A leaking under cleaning-in-place (CIP) conditions is not very clear and difficulties have been commonly encountered when improving the media's chromatographic performance. We investigated the chromatographic performance of site-directed coupled rProtein A chromatographic media during CIP procedure. Trace amount of ligands leaked during the chromatographic media's incubation in 0.5 M NaOH was detected, explaining for the decline of chromatographic media's CIP performance. Decrease of rProtein A's concentration in 0.5 M NaOH was consistent with chromatographic media's binding capacity. A novel rProtein A chromatographic media were prepared by site-directed coupling a newly-constructed alkali-resistant rProtein A to highly cross-linked agarose-based matrix. The media had a dynamic binding capacity of 63.2 mg hIgG/mL higher than 48.1 mg hIgG/mL of the commercial one, and the CIP performance was improved greatly with the remained dynamic binding capacity increased from 86% to 95% of the initial value after 40 CIP cycles.