title: Use of protein A-coated colloidal gold particles for immunoelectronmicroscopic localization of ACTH on ultrathin sections.
abstract: ACTH was localized in dissociated porcine adenohypophysial cells using a novel indirect EM immunocytochemical technique. Incubation of ultrathin resin sections in anti-ACTH was followed by incubation with protein A-coated colloidal gold particles. Protein A binds specifically to the Fc part of the IgG molecule, and thus the ACTH-containing secretory granules became labelled with electron-dense gold particles. With this method, the dissociated porcine ACTH cells was identified as containing numerous round or ovoid 170--300 nm secretory granules.
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000302:isolation & purification*; D000818:Animals; D000937:Antigen-Antibody Reactions; D002478:Cells, Cultured; D003102:Colloids; D003594:Cytoplasmic Granules / Q000032:analysis*; D006046:Gold; D008854:Microscopy, Electron / Q000379:methods*; D010903:Pituitary Gland, Anterior / Q000648:ultrastructure; D013205:Staphylococcal Protein A; D013552:Swine
chemical_list: D003102:Colloids; D013205:Staphylococcal Protein A; D006046:Gold; D000324:Adrenocorticotropic Hormone