Biomaterial Database

Use of tannic acid and silver enhancer to improve staining for electron microscopy and immunogold labeling. 1993

J W Stirling

Department of Histopathology, Flinders Medical Centre, Bedford Park, South Australia.

Staining by uranyl acetate and lead citrate (UA-LC) of immunolabeled sections of unfixed glomerular basement membrane (GBM) digests embedded in low-acid glycol methacrylate (LA-GMA) is poor. The following were investigated for their ability to enhance contrast when applied to sections before UA-LC: potassium permanganate, phosphotungstic acid, gold chloride, osmium tetroxide, glutaraldehyde-osmium tetroxide, colloidal gold-silver enhancer, tannic acid, and glutaraldehyde-tannic acid. Silver enhancer (2 min incubation, no sodium thiosulfate step) gave dense GBM staining but not with immunogold labeling. Silver enhancer is recommended as a simple alternative to routine silver stains but not for contrast enhancement with immunogold labeling. Tannic acid (1% for 1 min or 0.005% for 10 sec) and glutaraldehyde (2.5% for 5 min) followed by tannic acid enhanced contrast and, when applied after immunolabeling, did not appear to affect probe levels. Tannic acid also enhanced the staining of fixed tissue in LR Gold acrylic resin and LA-GMA, but not of glutaraldehyde-osmium-fixed tissue in epoxy resin, even after sodium metaperiodate treatment. Treatment of sections with tannic acid is recommended for contrast enhancement in immunogold studies when osmium and tannic acid post-fixation must be avoided and the tissue is embedded in methacrylate or acrylic resin.

UI	MeSH Term	Description	Entries
D007150	Immunohistochemistry	Histochemical localization of immunoreactive substances using labeled antibodies as reagents.	Immunocytochemistry,Immunogold Techniques,Immunogold-Silver Techniques,Immunohistocytochemistry,Immunolabeling Techniques,Immunogold Technics,Immunogold-Silver Technics,Immunolabeling Technics,Immunogold Silver Technics,Immunogold Silver Techniques,Immunogold Technic,Immunogold Technique,Immunogold-Silver Technic,Immunogold-Silver Technique,Immunolabeling Technic,Immunolabeling Technique,Technic, Immunogold,Technic, Immunogold-Silver,Technic, Immunolabeling,Technics, Immunogold,Technics, Immunogold-Silver,Technics, Immunolabeling,Technique, Immunogold,Technique, Immunogold-Silver,Technique, Immunolabeling,Techniques, Immunogold,Techniques, Immunogold-Silver,Techniques, Immunolabeling
D007678	Kidney Glomerulus	A cluster of convoluted capillaries beginning at each nephric tubule in the kidney and held together by connective tissue.	Glomerulus, Kidney
D008689	Methacrylates	Acrylic acids or acrylates which are substituted in the C-2 position with a methyl group.	Methacrylate
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
D006046	Gold	A yellow metallic element with the atomic symbol Au, atomic number 79, and atomic weight 197. It is used in jewelry, goldplating of other metals, as currency, and in dental restoration. Many of its clinical applications, such as ANTIRHEUMATIC AGENTS, are in the form of its salts.
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D001485	Basement Membrane	A darkly stained mat-like EXTRACELLULAR MATRIX (ECM) that separates cell layers, such as EPITHELIUM from ENDOTHELIUM or a layer of CONNECTIVE TISSUE. The ECM layer that supports an overlying EPITHELIUM or ENDOTHELIUM is called basal lamina. Basement membrane (BM) can be formed by the fusion of either two adjacent basal laminae or a basal lamina with an adjacent reticular lamina of connective tissue. BM, composed mainly of TYPE IV COLLAGEN; glycoprotein LAMININ; and PROTEOGLYCAN, provides barriers as well as channels between interacting cell layers.	Basal Lamina,Basement Lamina,Lamina Densa,Lamina Lucida,Lamina Reticularis,Basement Membranes,Densas, Lamina,Lamina, Basal,Lamina, Basement,Lucida, Lamina,Membrane, Basement,Membranes, Basement,Reticularis, Lamina
D013194	Staining and Labeling	The marking of biological material with a dye or other reagent for the purpose of identifying and quantitating components of tissues, cells or their extracts.	Histological Labeling,Staining,Histological Labelings,Labeling and Staining,Labeling, Histological,Labelings, Histological,Stainings
D016622	Silver Staining	The use of silver, usually silver nitrate, as a reagent for producing contrast or coloration in tissue specimens.	Silver Nitrate Staining,Nitrate Staining, Silver,Staining, Silver,Staining, Silver Nitrate
D016707	Tissue Fixation	The technique of using FIXATIVES in the preparation of cytologic, histologic, or pathologic specimens for the purpose of maintaining the existing form and structure of all the constituent elements.	Fixation, Tissue