Characterization of Humanized Anti-Tac Monoclonal Antibody by Traditional Separation Techniques and Capillary Electrophoresis

Abstract

Humanized anti-Tac monoclonal antibody has been characterized by both SDS-PAGE and isoelectric focusing using traditional polyacrylamide methods. In addition to these techniques, capillary electrophoresis has been adapted to isoelectric focusing in a liquid phase. The humanized antibody has a pl in the range of 8.2–9.0, a region in which precast polyacrylamide or agarose gels are not stable in the 7–10 pH range. Experiments have been conducted to generate gradients in the 3–10 pH range and these gradients have successfully separated differently charged subspecies of humanized anti-TAC. Because of the simplicity in generating a variety of gradients, the power of resolution in different modes, its high efficiency, and the minimum sample volume requirements, capillary electrophoresis may become the method of choice for the routine characterization of therapeutic monoclonal antibodies and their stability profiles.