Specificity and cross-reactivity of monoclonal antibodies against bovine insulin.

The positions of antigenic determinants were determined for six monoclonal antibodies against bovine insulin. Three antibodies bound to a determinant around amino acid residue A-10 and the other three to a determinant near the carboxy-terminal of the B-chain. The monoclonal antibodies discriminated between insulin of various species better than did a guinea pig anti-bovine insulin antiserum. One monoclonal antibody discriminated between porcine and human insulin and was used to show that, in principle, it is possible to determine the amount of porcine insulin contained in a mixture of porcine and human insulin.