Separation of the Isoforms of a Monoclonal Antibody by Gel Isoelectric Focusing, High Performance Liquid Chromatography and Capillary Isoelectric Focusing

摘要

The isoforms of a monoclonal antibody have been resolved by three different techniques: polyacrylamide gel isoelectric focusing, cation exchange HPLC, and capillary isoelectric focusing. The three techniques gave similar results; five major and one minor fraction were observed, corresponding to pIs in the pH range 6.0 to 6.5. The methods are compared and the advantages as well difficulties of each are discussed.