Production and Characterization of Monoclonal Antibodies Against Aflatoxin M1

By using an indirect enzyme-linked immunosorbent assay, four monoclonal antibodies were selected after fusion of mouse P3-NS1-Ag4-1 myeloma cells with spleen cells isolated from BALB/c mice that had been immunized with aflatoxin Ml (AFMI) conjugated to bovine serum albumin. Two of these antibodies were found to be specific for AFMI and were designated AMW-1 and AMW-4. The specificities of AMW-1, which had higher affinity to AFM1, were determined by a competitive direct enzyme-linked immunosorbent assay with peroxidase-AFMI as the marker. The relative cross-reactivity of each toxin (relative to AFMI) with AMW-1, as determined by the amount of aflatoxin necessary to cause 50% inhibition of enzyme activity, was 12, >40, 12, and >40 for B1, B2, Gl, and G2, respectively.