IMMUNOGOLD LABELING OF NEUROENDOCRINE PEPTIDES WITH SPECIAL REFERENCETO ANTIBODY SPECIFICITY AND MULTIPLE STAINING TECHNIQUES

Immunogold methods have been very important for research on the neuroe ndocrine system. The compatibility of immunogold probes with optimal c ontrasting for electron microscopy has made localizations of neuroendo crine peptides to different subtypes of secretory organelles possible and, currently, methods using covalent attachment of nanogold particle s to antibodies and neuropeptide ligands hold promise for immunocytoch emistry, receptor localizations and in situ hybridizations. Multihormo nal phenotypes are a hallmark of both the developing and mature neuroe ndocrine system. The possibility to localize multiple coexisting messe ngers by multilabelling immunogold methods is emphasized, and differen t methods for achieving this are discussed. The most difficult part of immunocytochemistry involves definitions and interpretations of speci ficity, and a number of limitations and control procedures are discuss ed.