A myeloma hybrid producing antibody specific for an allotypic determinant on “IgD‐like” molecules of the mouse

A hybrid cell line was produced by fusing a mouse myeloma line with spleen cells from BALB/c mice immunized with B10 cells. The hybrid line grew in tissue culture and in syngeneic mice and produced IgM antibody specific for "IgD-like" molecules of mice with the Igb haplotype. The concentration of monoclonal antibody in the serum of tumor-bearing animals reached about 2 mg/ml and gave cytotoxic titers of up to 1:800 000. The derivation of the line, some properties of the antibody secreted and the nature of its antigenic target are described.