Antibodies for Growth Hormone and Prolactin Using Multiple Antigen Peptide Immunogens

: Antibodies elicited by novel synthetic peptide antigens derived from a highly conserved domain of the growth hormone (GH) and prolactin (PRL) of vertebrates were developed using the multiple antigen peptide approach. The sequence of the antigens is located near the carboxy-terminus in the D domain of the GH and PRL in a cluster of 11 and 10 conserved amino acids, respectively, within a sequence of 18 residues. The synthetic peptides were manually synthesized, purified by high-performance liquid chromatography, and the corresponding antibodies, elicited in rabbits, were cross-reacted with the GH and PRL of a variety of mammalian (human, bovine, ovine, pig, and equine) and nonmammalian (chicken, coho salmon, chum salmon, rainbow trout, catfish and striped bass) vertebrates. The cross-reactivity between the immunogen and its corresponding antigen was tested by immunobloting using either GH or PRL. The GH and PRL of the organisms tested cross-reacted specifically with the corresponding antibody. Chicken and fish GH and PRL showed stronger antibody cross-reactivity than that observed in mammalian sources. These results demonstrate the utility of peptide-derived polyclonal antibodies in the detection of native and recombinant GH and PRL of a variety of vertebrates.