Mixing two monoclonal antibodies yields enhanced affinity for antigen

摘要: We observed that mixing monoclonal antibodies directed against various epitopes of human chorionic gonadotropin (hCG) can increase the sensitivity antigen-binding assays. Depending on antibody pair chosen, affinity mixture was as much 10-fold higher than either assayed separately. Because hCG does not have any repeating sequences, these results do reflect a change in avidity an individual antibody. The increased be detected both solid-phase assays and liquid-phase double radioimmunoassays. This general property all raised hCG. Certain antibodies, apparently reacting with same region antigen molecule, bind simultaneously result enhanced when mixed. In addition, certain other pairs cooperatively even though they simultaneously. mechanism for depends formation multicomponent complex. If one upon is replaced by its F(ab) fragment, enhancement no longer detectable, indicating it unlikely due to allosteric effect. Although F(ab')2 fragment shows some mixed another antibody, effective intact