Affinity chromatography for the capture of a biopharmaceutical, when available, is generally preferred because of its selectivity. Column loading optimization is thereafter an important issue because of resin cost. In this work, the Dynamic Binding Capacity (DBC) as a function of protein concentration is reported for commercially available Protein A resins and three proteins of different sizes. A 10-40% increase in the measured DBC is observed when the protein concentration in the feed increases from 1g/L to 5g/L. This behavior was investigated by measuring static binding capacity and diffusivity. The shape of the binding isotherm can be fitted using the colloidal isotherm and used to explain the increase in DBC observed experimentally. The accessible surface area was determined using inverse size exclusion chromatography to show that commercially available Protein A resins are optimized for IgGs, but not for smaller protein molecules.

Effect of titer on the development of an affinity chromatography step

243rd National Meeting (2012)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.