SIMULTANEOUS LOCALIZATION OF MULTIPLE TISSUE ANTIGENS USING THE PEROXIDASE-LABELED ANTIBODY METHOD: A STUDY ON PITUITARY GLANDS OF THE RAT

The peroxidase-labeled antibody method was modified to localize multiple tissue antigens in a single histologic section. The first antigen was localized by the indirect method and the antisera were removed from the section by elution, leaving the colored reaction products identifying the antigenic sites. The second and subsequent antigens were localized similarly, using substrates that develop reaction products of different colors. For the demonstration of the method, anti-human growth hormone (GH), anti-human thyrotropic hormone (TSH) and anti-human chorionic gonadotropin, which cross-reacts with rat luteinizing hormone (LH), were used with sections of pituitary gland of the rat. Anti-GH reacted with small acidophilic cells. Anti-LH was localized in oval shaped cells, and anti-TSH was localized in angulated basophilic cells. Some cells were devoid of these three antigens and no cell contained more than one of them.