Fractionation of monoclonal antibody aggregates using membrane chromatography

Monoclonal antibodies (mAbs) comprise an important class of biopharmaceuticals. Aggregation of mAbs is a common though undesirable occurrence. Size exclusion chromatography (SEC) which is used for both analysis and preparative separation of mAb aggregates is slow and results in poorly resolved peaks, particularly for higher order aggregates. We describe a hydrophobic interaction membrane chromatography (HIMC) based method for rapid and efficient separation and analysis of mAb aggregates. Our method was able to resolve Campath-1H monomer, dimer, trimer, tetramer and pentamer. The results obtained also strongly supported our hypothesis that the hydrophobicity of mAb increases with the degree of aggregation, i.e. a dimer is more hydrophobic than a monomer, a trimer more than a dimer, and so on.