Monoclonal antibodies (IgM) against a murine carcinoma, Lewis lung carcinoma (3LL): production, purification and in vitro selectivity.

C57BL/6 mice were immunized against a syngeneic murine carcinoma, Lewis lung carcinoma (3LL). Monoclonal antibodies were prepared by fusing spleen cells of immunized mice with SP2-O-Ag mouse myeloma cells. Hybridoma clones producing anti-3LL antibodies were selected on the basis of a solid-phase radioimmunoassay. Two clones were selected and subcloned to give the 5B5 and the 6B6 hybrid lines which were found to secrete IgM monoclonal antibodies. Large quantities of monoclonal antibodies were purified from ascitic fluids by gel filtration chromatography. Specificities of these antibodies were tested on 3LL tumor cells, 3LL metastases, lymphoid cells and leukemic L1210 cells. The 5B5 IgM monoclonal antibody was found to be selectively directed against primary tumor cells and metastatic cells.