title: Low vacuum scanning electron microscopy for paraffin sections utilizing the differential stainability of cells and tissues with platinum blue.
abstract: The present study introduces a novel method for the direct observation of histological paraffin sections by low vacuum scanning electron microscopy (LVSEM) with platinum blue (Pt-blue) treatment. Pt-blue was applied not only as a backscattered electron (BSE) signal enhancer but also as a histologically specific stain. In this method, paraffin sections of the rat tongue prepared for conventional light microscopy (LM) were stained on glass slides with a Pt-blue staining solution (pH 9) and observed in a LVSEM using BSE detector. Under LVSEM, overviews of whole sections as well as three-dimensional detailed observations of individual cells and tissues could be easily made at magnifications from x40 to x10,000. Each kind of cell and tissue observed in the section could be clearly distinguished due to the different yields of BSE signals, which depended on the surface structures and different affinities to Pt-blue. Thus, we roughly classified cellular and tissue components into three groups according to the staining intensity of Pt-blue observed by LM and LVSEM: 1) a strongly stained (deep blue by LM and brightest by LVSEM) group which included epithelial tissue, endothelium and mast cells; 2) a moderately stained (light blue and bright) group which included muscular tissue and nervous tissue; 3) an unstained or weakly stained (colorless and dark) group which included elastic fibers and collagen fibers. We expect that this method will prove useful for the three-dimensional direct observation of histological paraffin sections of various tissues by LVSEM with higher resolutions than LM.
authors.affiliation: Division of Genome Morphology, Department of Functional, Morphological and Regulatory Science, Faculty of Medicine, Tottori University, Yonago, Japan. sumire@med.tottori-u.ac.jp
authors.forename: Sumire
authors.initials: S
authors.lastname: Inaga
authors.forename: Sayuri
authors.initials: S
authors.lastname: Hirashima
authors.forename: Keiichi
authors.initials: K
authors.lastname: Tanaka
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Katsumoto
authors.forename: Toshio
authors.initials: T
authors.lastname: Kameie
authors.forename: Hironobu
authors.initials: H
authors.lastname: Nakane
authors.forename: Tomonori
authors.initials: T
authors.lastname: Naguro
mesh_terms: D000818:Animals; D003094:Collagen / Q000648:ultrastructure; D004396:Coloring Agents / Q000737:chemistry*; D004547:Elastic Tissue / Q000648:ultrastructure; D004727:Endothelium / Q000648:ultrastructure; D006863:Hydrogen-Ion Concentration; D008297:Male; D008407:Mast Cells / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning / Q000379:methods*; D009944:Organoplatinum Compounds / Q000737:chemistry*; D016612:Paraffin Embedding; D051381:Rats; D013194:Staining and Labeling; D013936:Thymidine / Q000031:analogs & derivatives* / Q000737:chemistry; D014618:Vacuum
chemical_list: D004396:Coloring Agents; D009944:Organoplatinum Compounds; D003094:Collagen; D013936:Thymidine