Incorporating ultrafiltration into Protein A membrane chromatography as a strategy to reduce elution volume and...

Protein A chromatography is widely used for antibody purification. With conventional packed-bed columns, mass transfer within resin beads is diffusion-limited, entailing long residence time to achieve high binding capacities. Recently, several vendors have introduced Protein A membranes as alternatives to traditional Protein A resins/columns. These membranes feature open pore structures that facilitate the convective transport of protein molecules, enabling high binding capacities within significantly shorter residence time. The use of Protein A membranes can improve throughput, eliminate the need for column packing, and reduce cost. These advantages notwithstanding, Protein A membranes present certain drawbacks. A major limitation is their high dead volume-to-stationary phase ratio, which leads to larger elution volumes compared to their conventional counterparts. This results in significant eluate dilution and increased buffer consumption.

In the current study, we aimed to demonstrate that ultrafiltration (UF), when used in combination with Protein A membrane chromatography, can address these limitations by allowing eluate concentration and buffer reuse.

A laboratory model of UF integrated Protein A membrane was set up to test the feasibility and effectiveness of the proposed strategy.

Integrated UF effectively concentrated Protein A membrane eluate to a concentration comparable to that of Protein A column eluate. In addition, reuse of pH-adjusted UF filtrate as elution buffer reduces buffer consumption by 50%.

UF integration is an effective solution for addressing the problem of increased elution volume and buffer consumption associated with Protein A membrane.