2.3. Protein solution characterization
Host cell protein (HCP) in the mAb solution was analyzed using CHO Host Cell Protein ELISA 3G Kit (Cygnus Technologies).
To determine the molecular weight distribution of proteins, size exclusion chromatography (SEC) was conducted. For analysis of mAb solutions, HPLC (Infinity 1260, Agilent) was used with a TSKgel SuperSW mAb HR column and a column guard (Tosoh). For analysis of plasma IgG solutions, HPLC (Acquity UPLC, H-Class Plus System, Waters) was conducted with a TSKgel UltraSW Aggregate column and TSKgel UltraSW Aggregate Guard column (7.8 mm ID, Tosoh BioScience LLC).
mAb and plasma IgG recovery for chromatography and filtration steps was determined by measuring UV absorbance at 280 nm before and after processing steps and calculating recovery as a percentage.