MS compatible charge variant analysis of 28 commercial monoclonal antibodies by CEX

Cation exchange chromatography (CEX) is perceived to be the gold standard for the charge sensitive characterisation of monoclonal antibodies (MAbs). Acidic and basic variants caused by chemical or enzymatic modifications can be separated from the main isoform of the MAb. These antibody variants have to be critically evaluated as differences in impurities and/or degradation products can lead to severe undesirable side effects.