title: Differential staining of mucin granules from epoxy resin sections by a phosphotungstic acid-methyl green procedure.
abstract: After treatment of epoxy resin semithin sections from glutaraldehyde fixed rat large intestine with 5% aqueous phosphotungstic acid (PTA), staining with unpurified 0.2% solutions of methyl green at 60 C for 5 min produces a color differentiation between mucin granules of goblet cells. Some mucin granules and the glycocalyx appear deep green while the remaining granules, luminal mucin and collagen fibers are pink. The known contamination of unpurified methyl green with crystal violet seems to be responsible for the pink staining reaction of the latter structures, which also present an orange-red fluorescence under green exciting light. Electron microscopic observations show selective contrast of mucin granules which appear with a different amount of PTA deposits. This procedure is useful to reveal the heterogeneity of mucin granules in light and electron microscopy.
authors.affiliation: Department of Animal Biology, Cell Biology and Parasitology, Faculty of Biology, University of Valencia, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Tato
authors.forename: M
authors.initials: M
authors.lastname: Planes
authors.forename: A
authors.initials: A
authors.lastname: Ramos
authors.forename: J C
authors.initials: JC
authors.lastname: Stockert
authors.forename: J M
authors.initials: JM
authors.lastname: Ferrer
mesh_terms: D000818:Animals; D003594:Cytoplasmic Granules / Q000648:ultrastructure*; D004853:Epoxy Resins; D005752:Gastric Mucins / Q000648:ultrastructure*; D005840:Gentian Violet; D007420:Intestine, Large / Q000033:anatomy & histology*; D008739:Methyl Green; D008854:Microscopy, Electron; D010772:Phosphotungstic Acid; D051381:Rats; D011919:Rats, Inbred Strains; D013194:Staining and Labeling
chemical_list: D004853:Epoxy Resins; D005752:Gastric Mucins; D010772:Phosphotungstic Acid; D008739:Methyl Green; D005840:Gentian Violet