title: Backscattered electron image of osmium-impregnated/macerated tissues as a novel technique for identifying the cis-face of the Golgi apparatus by high-resolution scanning electron microscopy.
abstract: The osmium maceration method with scanning electron microscopy (SEM) enabled to demonstrate directly the three-dimensional (3D) structure of membranous cell organelles. However, the polarity of the Golgi apparatus (that is, the cis-trans axis) can hardly be determined by SEM alone, because there is no appropriate immunocytochemical method for specific labelling of its cis- or trans-faces. In the present study, we used the osmium impregnation method, which forms deposits of reduced osmium exclusively in the cis-Golgi elements, for preparation of specimens for SEM. The newly developed procedure combining osmium impregnation with subsequent osmium maceration specifically visualised the cis-elements of the Golgi apparatus, with osmium deposits that were clearly detected by backscattered electron-mode SEM. Prolonged osmication by osmium impregnation (2% OsO4 solution at 40°C for 40 h) and osmium maceration (0.1% OsO4 solution at 20°C for 24 h) did not significantly impair the 3D ultrastructure of the membranous cell organelles, including the Golgi apparatus. This novel preparation method enabled us to determine the polarity of the Golgi apparatus with enough information about the surrounding 3D ultrastructure by SEM, and will contribute to our understanding of the global organisation of the entire Golgi apparatus in various differentiated cells.
authors.affiliation: Department of Microscopic Anatomy and Cell Biology, Asahikawa Medical University, Asahikawa, Japan.|Division of Microscopic Anatomy and Bio-imaging, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
authors.forename: D
authors.initials: D
authors.lastname: Koga
authors.affiliation: Department of Microscopic Anatomy and Cell Biology, Asahikawa Medical University, Asahikawa, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Bochimoto
authors.affiliation: Department of Microscopic Anatomy and Cell Biology, Asahikawa Medical University, Asahikawa, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Watanabe
authors.affiliation: Division of Microscopic Anatomy and Bio-imaging, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Ushiki
mesh_terms: D000818:Animals; D006056:Golgi Apparatus / Q000648:ultrastructure*; D008297:Male; D008855:Microscopy, Electron, Scanning / Q000379:methods*; D009992:Osmium; D051381:Rats; D017208:Rats, Wistar
chemical_list: D009992:Osmium
keywords: Backscattered electron; Golgi apparatus; cis-Golgi; osmium impregnation; osmium maceration; scanning electron microscopy