Rapid removal of host cell-related impurities, such as proteins and nucleic acids, is important in bioprocessing as they may enzymatically or otherwise alter target biopharmaceuticals. The presence of such contaminants can also reduce the safety and efficacy of biopharmaceuticals. The ability of Protein A-based affinity chromatography to rapidly decrease the levels of such contaminants in antibody target samples is well known. For many years the importance of intermediate Protein A column washing to reduce contaminant levels, while leaving target on the column, has been appreciated as it improves both target purity and column-life. This poster summarizes a detailed study of washing-buffer pH, salt-type, conductivity and additives on contaminant removal in Amsphere A3 affinity resin. The additives studied included chaotropic agents, organic solvents and surfactants. LC-MS was used to identify and monitor the removal of various Host Cell Proteins. Some noteworthy results are: Increasing NaCl in wash buffers up to 1M at pH 7.5 significantly reduced HCP levels from 7000 to 4500 parts per million (ppm). Further increasing NaCl to 2M had little effect. Increasing wash buffer pH from 5.5 to 9.5 reduced HCP from 7000 to 2000 ppm. DNA was reduced from 3000 to &lt;500 parts per billion (ppb) as NaCl went to 1M. DNA contamination was further reduced as buffer NaCl went from 1M to 2M. Some chaotropic agents were more effective than NaCl at reducing HCP and DNA. Some organic solvent additives reduced control HCP levels by over 80% but had much less effect on DNA contaminant levels. The presence of some surfactants reduced DNA contaminant levels by 70% but had little effect on HCP contaminant levels. In all cases studied, target recovery from Amsphere A3 was of 97±3%. In this poster the above results will be presented and discussed in more detail.

Improving removal of host cell-related impurities during protein A chromatography

ACS Fall 2021

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