Real-time kinetic analysis applied to the production of bispecific monoclonal antibodies for radioimmunodetection of cancer.

An automated biosensor system designed for measuring molecular interactions in real-time and without labelling of the reactants has been used to evaluate the association/dissociation rate and affinity constants of bivalent monoclonal antibodies and a monovalent bispecific monoclonal antibody. Observed differences in affinity between parental and bispecific antibody produced were related to the association rate constants, since the dissociation rate constants were in the same range. Values were also closely related to radioimmunochemical data. These results indicate that the biosensor system, besides presenting several advantages for characterizing antigen-antibody interaction, is valuable for selecting monoclonal antibodies with properties which might be useful in the development of bispecific monoclonal antibodies.