Immunoprecipitation of human H-Y antigen

Summary In the absence of beta-2-microglobulin and MHC-determined cell surface antigens, cultured cells of the Burkitt lymphoma, Daudi, secrete testis-inducing H-Y antigen into the surrounding medium. We have precipitated Daudi-secreted H-Y antigen by two methods, one using mouse H-Y antibody and goat anti-mouse Ig, and the other using mouse H-Y antibody and Sepharose beads coated with protein A. The estimated molecular weight of the specific immunoprecipitate was 15,000–18,000 Daltons.