Characterization of monoclonal antibodies against human chorionic somatomammotropin: competitive screening and determination of the affinity constants.

A simple screening method has been developed for the characterization of monoclonal antibodies (MAbs) against human chorionic somatomammotropin (hCS) produced in our laboratory. The method is easily adaptable to MAbs against other soluble antigens. Our proposed method allows evaluation of the degree of binding of the antibodies to the antigen, and of cross-reaction with human growth hormone and ovine prolactin. The positive clones have been further characterized by solid-phase radioimmunoassay in order to determine their affinity constants, which ranged from 10(7) to 10(9)/M as determined by non-linear regression analysis.