Production of monoclonal antibody to human IgG allotype G3M T

An efficient method for the production of monoclonal anti-G3M T antibody is described. IgG3 protein of GM B3ST phenotype was isolated by affinity chromatography on Ricinus communis lectin I-agarose and used for immunization. A mouse hybridoma clone was obtained by fusion of popliteal lymph node cells and P3U1 myeloma cells. The antibody produced was tested for allotype specificity by hemagglutination inhibition and ELISA methods using 101 IgG-allotyping control sera. The antibody was neutralizable by all G3M T-positive sera and entirely nonneutralizable by G3M T-negative sera in the inhibition test, and reacted only with G3M T-positive IgG coats in the ELISA test. The results prove the antibody to be allotype-specific, and therefore practically establishes its monoclonality.