Monoclonal antibodies to hypothalamic growth hormone-releasing factor with picomoles of antigen.

Monoclonal antibodies specific for rat hypothalamic growth hormone-releasing factor (rGRF) have been produced by in vitro immunization of mouse spleen cells with less than 1 nanomole of rGRF in a partially purified preparation. Hybridoma supernatants were screened for anti-rGRF activity by use of a pituitary culture assay system that can detect growth hormone-releasing factor in the femtomole range. Such highly sensitive in vitro techniques permit the use of picomole quantities of an antigen in partially purified preparations for the isolation of monoclonal antibodies, which can in turn be used in biological studies and in immunochemical procedures for large-scale purification and isolation of that antigen.