[Monoclonal antibodies to mouse alpha-fetoprotein]

Splenocytes of rats immunized with mouse alpha-fetoprotein (MAFP) and cells of mouse myeloma NS-I were used to obtain hybridomas that synthesize antibodies to MAFP (anti-MAFP). Antibody activity was determined by the two tests: solid-phase ELISA and indirect immunoperoxidase staining of the regenerating liver sections of mice poisoned with CCl4. After recloning of one of the hybridomas a clone that effectively synthesized anti-MAFP was selected and reproduced. Anti-MAFP were isolated from cultural fluid of the clone by sorption-elution on CnBr-activated sepharose 4B conjugated with purified MAFP. Monoclonal origin of anti-MAFP has been demonstrated by electrophoretic homogeneity of the preparation, and by its appurtenance to one of the subclasses of rat IgG. Anti-MAFP does not precipitate MAFP but distinctly inhibits the formation of the precipitation line by MAFP and rabbit antibodies to MAFP in the zone of diffusion of monoclonal antibodies. Monoclonal anti-MAFP were high-effective in the reaction with MAFP in both tests. Anti-MAFP specificity is directed to one of the MAFP determinants that is common to rat and human alpha-fetoprotein.