Quantification of monoclonal antibodies in complex mixtures by protein G high-performance liquid affinity chromatography.

High-performance liquid affinity chromatography (HPLAC) utilizing Protein G as a ligand has been evaluated for rapid quantification of monoclonal antibodies (MAbs) in various solutions. The results obtained by HPLAC agreed to within 10% of a standard enzyme-linked immunospecific assay (ELISA). A standard curve was prepared by injection of known amounts of a purified murine IgG1 with the elution peak area analyzed by computer integration software. Accuracy of quantification was independent of the injection volume, solution compositions, or mouse IgG subclass. A method is described for using Protein G HPLAC to determine murine IgG levels in various complex mixtures within 15 min, compared to the ELISA which required 5 h.