ABSTRACT
OBJECTIVE: To establish a capillary zone electrophoresis(CZE) -based method for charge heterogeneity analysis of IgG2 monoclonal antibody. METHODS: The concentrations of TETA and EACA, pH of separation buffer and temperature of capillary were optimized, to obtain a method which can efficiently separate the charge variants of IgG2 mabs. The reproducibility and repeatability of the optimized CZE method were validated and a battery of mabs were evaluated. RESULTS: The separation effect was significantly influenced by TETA/EACA concentration, pH and separation temperature. Through a series of optimization, a CZE method which showed good resolution and precision(RSD of area percentage was below 3.0% was established and the method parameters were as below: 400 mmol•L-1 EACA/0.05% TETA, pH 6.2, separation under 30 kV voltage at 35℃. This method was also suitable for IgG1 and IgG4 mabscharge heterogeneity analysis. Based on the specific electrophorogram and migration time, it could also be used as an identification method for monoclonal antibodies. CONCLUSION: The optimized CZE method can efficiently separate the charge variants of IgG2 mabs and shows good precision and specificity, which can be used to analyze the charge heterogeneity and identification of monoclonal antibodies.