Production and characterization of mouse monoclonal antibodies recognizing multiple subclasses of human IgG

Background: Pan-IgG specific monoclonal antibodies (MAbs) are essential tools for assessment of humoral immunity, immune deficiency and gam-mopathy. In this study, four hybridoma clones producing MAbs with different specificities for human IgG isotypes were established. Methods: Splenocytes from Balb/c mice immunized with Fc fractions of human IgG were fused with SP2/0 myeloma cells. Hybridoma cells were selected in HAT selective medium and cloned by limiting dilution assay. Antibody-secret-ing cells were screened by enzyme-linked immunosorbent assay (ELISA) and the specificity of secreted MAbs was further analyzed using a panel of purified myeloma IgG proteins by ELISA and immunoblotting. Cross-reactivity to im-munoglobulins (Igs) of other species was studied by indirect ELISA using serum samples collected from 9 animals. Results: Immunoblotting studies revealed recognition of either linear or con-formational epitopes by these MAbs. The most abundant cross-reactivit