Combined Protein A and size exclusion high performance liquid chromatography for the single-step measurement of mAb, aggregates and host cell proteins

• Combine two analytical chromatography column assays into one.
• Confirm performance of combined assays against ELISA, Bradford, and size exclusion.
• mAb quantitation for the combined column assay closely matches size exclusion.
• mAb aggregate quantitation captures the trend.
• Quantify relative increases in HCP concentration as accurately as the ELISA.

Quantification of monoclonal antibody (mAb) monomer, mAb aggregates, and host cell proteins (HCPs) is critical for the optimization of the mAb production process. The present work describes a single high throughput analytical tool capable of tracking the concentration of mAb, mAb aggregate and HCPs in a growing cell culture batch. By combining two analytical HPLC methods, Protein A affinity and size-exclusion chromatography (SEC), it is possible to detect a relative increase or decrease in the concentration of all three entities simultaneously. A comparison of the combined Protein A-SEC assay to SEC alone was performed, demonstrating that it can be useful tool for the quantification of mAb monomer along with trending data for mAb aggregate and HCP. Furthermore, the study shows that the Protein A-SEC method is at least as accurate as other commonly used analytical methods such as ELISA and Bradford.