Localization of murine Ig-1b and Ig-1a (IgG 2a) allotypic determinants detected with monoclonal antibodies

We have used hybridoma anti-allotype antibodies to define six allotypic determinants: four on Ig-1b molecules and two on Ig-1a molecules. By locating these determinants on fragments obtained by limited proteolysis of IgG 2a, molecules and by hybridoma antibody blocking assays, five distinct allotypic sites have been defined on mouse γ 2a heavy chains. These sites are located in the hinge region and the C H2 and C H3 domains. We have not been able to show genetic recombination between these sites by genetic linkage studies.