MAb Aggregate Removal through IEC in Bind/Elute and Flow-Through Mode

Purification schemes for monoclonal antibodies typically consist of three chromatographic steps accompanied by filtration steps. The common Protein A capturing is typically followed by ion exchange (IEC), hydrophobic interaction (HIC) or mixed-mode polishing steps. Residual DNA, viruses, and host cell proteins are usually removed by flow-through anion exchange chromatography while aggregates can be reduced through a cation exchange, mixed-mode, or HIC step.

The salt tolerant anion exchange resin TOYOPEARL NH2-750F provides a unique selectivity compared to other anion exchange resins and was found to be suited for aggregate removal, too. Herein we describe the development of an anion exchange polishing step for the purification of a monoclonal antibody by using TOYOPEARL NH2-750F. In general, anion exchange resins can be used in bind and elute (B/E) mode as well as in flow-through (FT) mode. Both options were evaluated. To increase the amount of aggregates of the test sample, a monoclonal antibody was aggregated by acidic incubation and subsequently diluted to 1 g/L in loading buffer.