A search for hapten-binding mouse plasmacytoma proteins.

Six hundred and twelve mouse plasmacytomas were screened for hapten binding by using eleven different bacteriophage-hapten conjugates (phage T4 conjugated with haptens NP, NIP, DIP, DNP,BOC-ABA-Tyr, ABA-NP, ABA-MIP, ABS-HOP, PAB-HOP, penicillin G, cloxacillin). Fifteen ascites fluids (2.4%) inactivated at least one of the phage conjugates at a high dilution indicating binding. The specificity of these reactions was studied by titrating one ascites fluid with phage conjugates carring unrelated haptens, and by inhibiting the phage inactivation with free haptens. Of the 15 myeloma proteins, 10 had high titers (at least 30 times higher than the ascites fluid background) with the NIP-cap phage or the NP-cap phage or both. Four had high titers with the DNP-cap phage and one with the ABA-MIP phage. Thirteen of the 15 myeloma proteins were IgA, one was IgM and one IgG2b.