Monoclonal anti‐idiotype (Id) antibodies with specificities for determinants related to the antigen‐binding sites of 3 BALB/c myeloma proteins, MOPC‐460, HOPC‐8 and J558, were used to study Id expression on murine lymphocytes. The monoclonal antibodies were shown to react only with Id structures associated with immunoglobulin on B cells. None of these 3 Id nor a VH Id, detected by a monoclonal antibody made against HOPC‐8 heavy chain, were found on T cells. These Id were detected on splenic B cells in neonatal mice; the frequencies in normal, nude and germ‐free mice were similar: MOPC‐460 Id+: 1.05 ± 1.7/104 spleen cells, HOPC‐8 Id+: 1.45 ± 1.2/104 and J558: 0.35 ± 0.6/104. Almost all Id+ cells bore surface IgM, a few expressed surface IgG. MOPC‐460 Id+ IgG+ cells were mainly γ2a+ or γ2b+, whereas J558 and HOPC‐8 Id+ IgG+ cells were γ3+. Copyright © 1984 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim
