CHARACTERIZATION OF IMMUNOCHEMICAL REACTION FOR HUMAN GROWTH-HORMONE WITH ITS MONOCLONAL-ANTIBODY BY PERFUSION PROTEIN-G AFFINITY-CHROMATOGRAPHY AND CAPILLARY ZONE ELECTROPHORESIS

An extremely rapid assay technique for antibody-antigen interaction us ing human growth hormone and its monoclonal antibody as an example has been developed by utilizing Protein G bound to perfusion chromatograp hy matrices. The antibody and antigen were mixed and incubated at diff erent molar ratios by keeping the concentration of antibody constant, The mixture of antibody and antigen solution was then injected onto th e Protein G column. The complex of antibody and antigen formed in the sample solution was retained on the Protein G column as was the free a ntibody. The peak-area and height of the retained complex and antibody linearly increased with the molar concentration of the antigen when i t was not in excess of the corresponding stoichiometric amount of anti body, however, those of the retained peak were constant when the conce ntration of antigen was in excess of that of the antibody, The validit y of this method was confirmed by the results of capillary zone electr ophoresis, The method developed cannot only be used to determine the b iological activity between antibody and its antigen quickly, but also to determine the stoichiometry of immunological reactions between the antibody and antigen when a stable complex of them can be formed.