Monoclonal antibodies directed against two different corticotropin-releasing factor determinants

Two hybridomas secreting monoclonal antibodies (mAbs) against human/rat corticotropin-releasing factor (CRF) have been produced by the cell fusion technique. Isotyping of the mAbs revealed that both belong to the IgG1 subclass. Human serum containing CRF-binding protein inhibits the binding protein inhibits the binding of CRF to both mAbs. Modification of lysine residue inhibits binding of the mAbs in a different manner. Affinity constants of binding with native and histidine-modified antigens have been determined by ELISA. The epitope specificity of the mAbs has been examined in competition experiments. No competition was detected, suggesting that the mAbs recognize different antigenic determinants. Two monoclonal antibodies can be employed in a two-site assay to measure CRF.