title: Use of 1.4-nm immunogold particles for immunocytochemistry on ultra-thin cryosections.
abstract: We present a new application for the use of small immunogold particles (approximately 1.4-nm diameter) for ultrastructural immunocytochemistry. These small gold particles have been used on ultra-thin cryosections in conjunction with a silver enhancement procedure that does not degrade ultrastructural detail. We have used the human neutrophil as a model system, in which known protein markers of two different cytoplasmic granules were localized, in the development of this procedure. The 1.4-nm immunogold particles coupled with silver enhancement yield intense labeling for localization of lactoferrin, a marker for the specific granules, and myeloperoxidase, a marker for the azurophil granules. Double labeling in which one antigen was visualized with 1.4-nm gold and silver enhancement and a second antigen was detected with colloidal gold-IgG on the same ultra-thin cryosection was successfully achieved. We also show that 1.4-nm diameter immunogold particles penetrate into cryosectioned neutrophils to a greater extent than 5-nm or 10-nm immunogold probes. These results show that small immunogold particles, along with silver enhancement, are a useful addition to the immunolabeling methods available for use with ultra-thin cryosections.
authors.affiliation: Department of Cell Biology, Neurobiology and Anatomy, Ohio State University, Columbus.
authors.forename: T
authors.initials: T
authors.lastname: Takizawa
authors.forename: J M
authors.initials: JM
authors.lastname: Robinson
mesh_terms: D003594:Cytoplasmic Granules / Q000737:chemistry / Q000201:enzymology / Q000648:ultrastructure; D005455:Fluorescent Antibody Technique; D017979:Gold Colloid; D006651:Histocytochemistry; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods*; D007781:Lactoferrin / Q000032:analysis*; D008854:Microscopy, Electron; D009504:Neutrophils / Q000737:chemistry* / Q000201:enzymology / Q000648:ultrastructure; D009195:Peroxidase / Q000032:analysis*; D016622:Silver Staining
chemical_list: D017979:Gold Colloid; D009195:Peroxidase; D007781:Lactoferrin