- stain
- 1. To discolor. 2. To color; to dye. 3. A discoloration. 4. A dye used in histologic and bacteriologic technique. 5. A procedure in which a dye or combination of dyes and reagents is used to color the constituents of cells and tissues. For individual dyes or staining substances, see the specific names. [M.E. steinen]- Abbott s. for spores spores are stained blue with alkaline methylene blue; bodies of the bacilli become pink with eosin counterstain.- acid s. a dye in which the anion is the colored component of the dye molecule, e.g., sodium eosinate (eosin).- Albert s. a s. for diphtheria bacilli and their metachromatic granules; contains toluidine blue, methyl green, glacial acetic acid, alcohol, and distilled water.- Altmann anilin-acid fuchsin s. a mixture of picric acid, anilin, and acid fuchsin which stains mitochondria crimson against a yellow background.- auramine O fluorescent s. a rapid and accurate technique for Mycobacterium tuberculosis, using auramine O -phenol and a methylene blue counterstain.- basic s. a dye in which the cation is the colored component of the dye molecule that binds to anionic groups of nucleic acid s (PO4Ξ) or acidic mucopolysaccharides ( e.g., chondroitin sulfate).- basic fuchsin-methylene blue s. a s. for intact epoxy sections; semithick sections of plastic-embedded tissues have nuclei stained purple; collagen, elastic lamina, and connective tissue are stained blue; mitochondria, myelin, and lipid droplets are stained red; cytoplasm, smooth muscle cells, axoplasm, and chrondroblasts are stained pink.- Bauer chromic acid leucofuchsin s. a s. for glycogen and fungi utilizing chromic acid as an oxidizing agent of polysaccharides, followed by Schiff reagent; glycogen and fungi cell walls appear deep red.- Becker s. for spirochetes a s. applied to thin films fixed in formaldehyde-acetic acid; preparations are treated successively with tannin, carbolic acid, and carbol fuchsin.- Bennhold Congo red s. an amyloid s. useful for amyloid detection in pathologic tissue; gives red staining of amyloid; also induces green birefringence to amyloid under polarized light.- Berg s. a method for staining spermatozoa, utilizing a carbol-fuchsin solution followed by dilute acetic acid and methylene blue; spermatozoa are stained a brilliant red and most other structures appear blue to purple.- Bielschowsky s. a method of treating tissues with silver nitrate to demonstrate reticular fibers, neurofibrils, axons, and dendrites.- Birch-Hirschfeld s. an obsolete s. for demonstrating amyloid, using Bismarck brown and crystal violet; amyloid is usually stained a bright ruby red, whereas the cytoplasm of cells is not stained and nuclei are brown.- Bodian copper-protargol s. a s. employing a silver proteinate complex (protargol) to demonstrate axis cylinders and neurofibrils.- Borrel blue s. a s. for demonstrating spirochetes, treponemes, and Borrelia organisms, using silver oxide (prepared by means of mixing solutions of silver nitrate and sodium bicarbonate) and methylene blue.- Bowie s. a s. for juxtaglomerular granules in which the kidney sections are stained in a mixture of Biebrich scarlet red and ethyl violet; juxtaglomerular granules and elastic fibers are stained a deep purple, erythrocytes are amber, and background tissue appears in shades of red.- Brown-Brenn s. a method for differential staining of Gram-positive and Gram-negative bacteria in tissue sections; it utilizes a modified Gram s. of crystal violet, Gram iodine, and basic fuchsin.- Cajal astrocyte s. a method for demonstrating astrocytes by impregnation in a solution containing gold chloride and mercuric chloride.- carbol-thionin s. a s. useful for demonstrating typhoid bacilli in films and sections, and for Nissl substance.- C-banding s. a selective chromosome banding s. used in human cytogenetics, employing Giemsa s. after most of the DNA is denatured or extracted by treatment with alkali, acid, salt, or heat; only heterochromatic regions close to the centromeres and rich in satellite DNA s., with the exception of the Y chromosome, whose long arm usually stains throughout. SYN: centromere banding s..- chromate s. for lead a method in which tissues preserved in chromate-containing fixatives, such as Regaud or Orth fixatives, precipitate lead as yellow lead chromate crystals; formalin-fixed sections are treated with potassium chromate acidified with acetic acid.- chrome alum hematoxylin-phloxine s. a s. used to demonstrate pancreatic islet cells; alpha cells appear red, beta cells blue or unstained.- Ciaccio s. a method for demonstrating complex insoluble intra-cellular lipids using fixation in a formalin-dichromate solution, embedding in paraffin, staining with Sudan III or IV, and examination in aqueous mountant.- contrast s. a dye used to color one portion of a tissue or cell which remained unaffected when the other part was stained by a dye of different color. SYN: differential s..- Da Fano s. a silver s. that produces a blackening of Golgi elements after tissues are fixed in a mixture of nitrate and formalin.- Dane s. a s. for prekeratin, keratin, and mucin that employs hemalum, phloxine, Alcian blue, and orange G; nuclei appear orange to brown, acid mucopolysaccharides pale blue, and keratins orange to red-orange.- DAPI s. a sensitive fluorescent probe for DNA, 4′6-diamidino-2-phenylindole 2HCl, used in fluorescence microscopy to detect DNA in yeast mitochondria, chloroplasts, viruses, mycoplasma, and chromosomes; DNA is visualized in vitally stained living cells and after cells are fixed in formaldehyde.- diazo s. for argentaffin granules in enterochromaffin cells, a variety of diazonium salts are used to blacken the cells.- Dieterle s. s. used to demonstrate spirochetes and Leishman-Donovan bodies; employs silver nitrate and uranium nitrate.- differential s. SYN: contrast s..- Ehrlich acid hematoxylin s. an alum type of hematoxylin s. used as a regressive staining method for nuclei, followed by differentiation to required staining intensity; the solution may be allowed to ripen naturally in sunlight or partially oxidized with sodium iodate.- Ehrlich triacid s. a differential leukocytic s. comprised of saturated solutions of orange G, acid fuchsin, and methyl green.- Einarson gallocyanin-chrome alum s. a method for staining both RNA and DNA a deep blue; with proper controls, nucleic acid content of stained cells and nuclei may be estimated by cytophotometry; also useful for Nissl substance.- Eranko fluorescence s. exposure of frozen sections to formaldehyde that produces a strong yellow-green fluorescence from cells containing norepinephrine.- Feulgen s. a selective cytochemical reaction for DNA in which sections or cells are first hydrolyzed with hydrochloric acid to produce apurinic acid and then are stained with Schiff reagent to produce magenta-stained nuclei; generally the concentration of DNA in nucleoli and mitochondria is too low to permit detection by this s. SEE ALSO: Kasten fluorescent Feulgen s..- Field rapid s. a s. to permit rapid positive diagnosis of malaria in endemic areas by using thick films; it employs methylene blue and azure B in a phosphate buffer, with the preparation counterstained by eosin in a phosphate buffer.- Fink-Heimer s. a method used for histologic demonstration of degenerating nerve fibers and terminals of the central nervous system (black on a yellow background).- fluorescence plus Giemsa s. a s. used to demonstrate sister chromatid exchange; cells are grown in 5-bromodeoxyuridine, followed by chromosome preparation, staining in Hoechst 33258, exposure to light, and staining in Giemsa; chromosomes exhibit a “harlequin” appearance.- fluorescent s. a s. or staining procedure using a fluorescent dye or substance that will combine selectively with certain tissue components and that will then fluoresce upon irradiation with ultraviolet or violet-blue light.- Fontana s. a traditional method for silver impregnation of treponemes and other spirochetal forms.- Foot reticulin impregnation s. a silver s. in which reticulin stains black and collagen stains golden brown; sections are floated on the surface of solutions to avoid contamination with silver debris.- Fouchet s. Fouchet reagent employed to demonstrate bile pigments; paraffin sections are used for conjugated bile pigments, frozen sections for unconjugated ones.- Fraser-Lendrum s. for fibrin a multistaining procedure after Zenker fixative in which fibrin, keratin, and some cytoplasmic granules appear red, erythrocytes appear orange, and collagen appears green.- Friedländer s. for capsules an obsolete s. employing gentian violet.- G-banding s. a chromosome-staining technique used in human cytogenetics to identify individual chromosomes which produces characteristic bands; it utilizes acetic acid fixation, air drying, denaturing chromosomes mildly with proteolytic enzymes, salts, heat, detergents, or urea, and finally Giemsa s.; chromosome bands appear similar to those fluorochromed by Q-banding s.. SYN: Giemsa chromosome banding s..- Giemsa s. compound of methylene blue -eosin and methylene blue used for demonstrating Negri bodies, Tunga species, spirochetes and protozoans, and differential staining of blood smears; also used for chromosomes, sometimes after hydrolyzing the cytologic preparation in hot hydrochloric acid, and for showing chromosome G bands; often used in glycerol-methanol buffer solution.- Glenner-Lillie s. for pituitary a modification of Mann methyl blue -eosin s. that changes the dye proportions, buffering the dye mixture, and staining at 60°C; basophils are stained blue to black, acidophils are dark red, chromophobe granules are gray to pink, and erythrocytes are orange; with modification, the method is also useful for enterochromaffin cells, goblet cells, Paneth cells, and pancreatic islet cells.- Golgi s. any of several methods for staining nerve cells, nerve fibers, and neuroglia using fixation and hardening in formalin-osmic-dichromate combinations for various times, followed by impregnation in silver nitrate.- Gomori aldehyde fuchsin s. a s. used to demonstrate beta cells of the pancreas, storage form of thyrotrophic hormone in beta cells of the anterior pituitary, hypophyseal neurosecretory substance, mast cells, granules, elastic fibers, sulfated mucins, and gastric chief cells.- Gomori chrome alum hematoxylin-phloxine s. a technique used to demonstrate cytoplasmic granules, after Bouin or formalin-Zenker fixatives, using oxidized hematoxylin plus phloxine; in the pancreas, beta cells are blue, alpha and delta cells are red, and zymogen granules are red to unstained; in the pituitary, alpha cells are pink, beta cells and chromophobes are gray-blue, and nuclei are purple to blue.- Gomori-Jones periodic acid -methenamine-silver s. a staining method using methenamine silver, periodic acid, gold chloride, hematoxylin, and eosin to delineate basement membrane, reticulin, collagen, and nuclei; used in renal histopathology. SEE ALSO: Rambourg periodic acid -chromic methenamine-silver s..- Gomori methenamine-silver s. (GMS) techniques for 1) argentaffin cells: a method using a methenamine-silver solution in combination with gold chloride, sodium thiosulfate, and safranin O; argentaffin granules appear brown-black against a green background; 2) urates: warm sections are treated directly with a hot methenamine-silver solution to produce a blackening of urates; 3) fungi: see Grocott-Gomori methenamine-silver s.; 4) melanin, which reduces silver nitrate.- Gomori nonspecific acid phosphatase s. a method in which formalin-fixed frozen sections are incubated in a substrate containing sodium β-glycerophosphate and lead nitrate at pH 5.0; the insoluble lead phosphate produced is treated with ammonium sulfide to give a black lead sulfide.- Gomori nonspecific alkaline phosphatase s. a calcium-cobalt sulfide method using frozen sections or cold acetone- or formalin-fixed paraffin sections, plus sodium β-glycerophosphate as a substrate at pH 9.0–9.5 with Mg2+ as activator; calcium ions precipitate the liberated phosphate, cobalt salt replaces the calcium phosphate, and ammonium sulfide converts the product to a black cobalt sulfide.- Gomori one-step trichrome s. a connective tissue s. that uses hematoxylin and a dye mixture containing chromotrope 2R and light green or aniline blue; muscle fibers appear red, collagen is green (or blue if aniline blue is used), and nuclei are blue to black.- Gomori silver impregnation s. a reliable method for reticulin, as an aid in the diagnosis of neoplasm and early cirrhosis of the liver; the staining solution employs silver nitrate, potassium hydroxide, and ammonia water carefully prepared to avoid having silver precipitate.- Gordon and Sweet s. a s. for reticulin, using acidified potassium permanganate, oxalic acid, iron alum, silver nitrate, formaldehyde, gold chloride, and sodium thiosulfate.- Gram s. a method for differential staining of bacteria; smears are fixed by flaming, stained in a solution of crystal violet, treated with iodine solution, rinsed, decolorized, and then counterstained with safranin O; Gram-positive organisms s. purple-black and Gram-negative organisms s. pink; useful in bacterial taxonomy and identification, and also in indicating fundamental differences in cell wall structure.- Gram-chromotrope s. a modified trichrome s. for microsporidian spores that combines Gram-s. reagents in the procedure.- green s. a deposit, produced by chromogenic bacteria, found on the cervicolabial portions of the teeth, usually in children. SEE ALSO: acquired pellicle.- Gridley s. for fungi a method for fixed tissue sections based on Bauer chromic acid leucofuchsin s. with the addition of Gomori aldehyde fuchsin s. and metanil yellow as counterstains; against a yellow background, hyphae, conidia, yeast capsules, elastin, and mucin appear in different shades of blue to purple.- Grocott-Gomori methenamine-silver s. a modification of Gomori methenamine-silver s. for fungi in which sections are pretreated with chromic acid before addition of the methenamine-silver solution and then counterstained with light green to demonstrate black-brown fungi against a pale green background.- Hale colloidal iron s. a s. used to distinguish acid mucopolysaccharides such as hyaluronic acid; may be combined with PAS to also visualize carbohydrate-containing proteins and glycoproteins.- Heidenhain azan s. a technique using azocarmine B or G followed by aniline blue to s. nuclei and erythrocytes red, muscle orange, glia fibrils reddish, mucin blue, and collagen and reticulum dark blue. [azocarmine + aniline blue]- Heidenhain iron hematoxylin s. an iron alum hematoxylin s. used for staining muscle striations and mitotic structures blue-black.- hematoxylin and eosin s. probably the most generally useful of all staining methods for tissues; nuclei are stained a deep blue with hematoxylin, and cytoplasm is stained pink after counterstaining with eosin, usually in water.- hematoxylin-malachite green -basic fuchsin s. a s. for epoxy resin-extracted sections; semithick sections have their plastic dissolved out and the residual tissue is stained sequentially with the various dyes; nuclei and astrocytes are purplish-pink and myelin, lipid droplets, nucleoli, and oligodendrocytes are bright blue-green.- hematoxylin-phloxine B s. a s. for intact epoxy sections; semi-thick sections of plastic-embedded tissues have the following structures stained blue to black: chromatin, nucleoli, basophilic cytoplasm, mitochondria, plasma and nuclear membranes, anisotropic myofibrils, mast cell granules, and elastic membranes of blood vessel s; appearing pink to red are collagen fibrils, reticulum, goblet cell mucins, hyalin cartilage matrix, stereocilia, cytoplasm, and erythrocytes; fat droplets and perichondrocyte matrix are green.- Hirsch-Peiffer s. a s. used for cytologic demonstration staining of metachromatic leukodystrophy; excess sulfatides s. metachromatically (golden brown) with cresyl violet in acetic acid.- Hiss s. a s. for demonstrating the capsules of microorganisms, using gentian violet or basic fuchsin followed by a copper sulfate wash.- Hortega neuroglia s. one of several silver carbonate methods to demonstrate astrocytes, oligodendroglia, and microglia.- immunofluorescent s. s. resulting from combination of fluorescent antibody with antigen specific for that antibody.- India ink capsule s. a negative s. for crystal bacteria in which cells appear purple (Gram crystal violet) and the capsules appear clear against a dark background.- intravital s. a s. which is taken up by living cells after parenteral administration, e.g., intravenously or subcutaneously.- iodine s. a s. to detect amyloid, cellulose, chitin, starch, carotenes, and glycogen, and to s. amebas by virtue of their glycogen; feces and other wet preparations are stained directly with Lugol iodine solution; smears are treated with Schaudinn fixative and then stained with alcoholic iodine, followed by Heidenhain iron hematoxylin.- Jenner s. a methylene blue eosinate similar to Wright s. but differing in not using polychromed methylene blue; used for staining of blood smears.- Kasten fluorescent Feulgen s. a fluorescent modification of the Feulgen s., utilizing any one of a variety of fluorescent basic dyes to which SO2 is added; the brilliant fluorescence makes this method unusually sensitive and adaptable to cytofluorometric quantification of DNA.- Kasten fluorescent PAS s. a fluorescent modification of the periodic acid -Schiff s. for polysaccharides which uses one of Kasten fluorescent Schiff reagents.- Kinyoun s. a method for demonstrating acid-fast microorganisms, using carbol fuchsin, acid alcohol, and methylene blue; acid-fast microorganisms appear red against a blue background.- Kleihauer s. a combination of aniline blue and Biebrich scarlet red used for detection of fetal cells in the maternal blood.- Klinger-Ludwig acid-thionin s. for sex chromatin a method using a preliminary acid treatment on buccal smears, prior to staining with buffered thionin, to differentiate Barr body.- Klüver-Barrera Luxol fast blue s. in combination with cresyl violet, a s. useful for demonstrating myelin and Nissl substance.- Kokoskin s. a modified trichrome s. for microsporidian spores in which heat is used to shorten the staining times.- Kronecker s. a 5% sodium chloride s. rendered faintly alkaline with sodium carbonate, used in the examination of fresh tissues under the microscope.- lactophenol cotton blue s. a solution consisting of phenol crystals, glycerol, lactic acid, and distilled water to which cotton blue or crystal violet is added; used as a s. in mycology.- Laquer s. for alcoholic hyalin a combination of Altmann aniline-acid fuchsin s. with a Masson trichrome s. which, on a gray-brown background, stains alcoholic hyalin red, collagen green, and nuclei brown.- lead hydroxide s. a s. for electron microscopy; after aldehyde fixation, alkaline lead hydroxide preferentially stains RNA, but after OsO4 fixation, it reacts largely with osmium in tissues to give a general s.; in addition to binding to cytomembranes, it also stains carbohydrates ( e.g., glycogen).- Lendrum phloxine-tartrazine s. a s. for demonstrating acidophilic inclusion bodies, which appear red on a yellow background; nuclei s. blue, but Negri bodies do not s..- Lepehne-Pickworth s. a staining technique for hemoglobin and other heme-containing substances in cryostat or frozen sections, which utilizes the presence of tissue peroxidase to oxidize benzidine to a blue quinhydrone.- Lillie allochrome connective tissue s. a procedure using PAS, hematoxylin, picric acid, and methyl blue; used for distinction between basement membrane and reticulin, and for demonstration of arteriosclerotic lesions.- Lillie azure-eosin s. a s. in which an azure eosinate solution is used to s. bacteria and rickettsiae in tissues.- Lillie ferrous iron s. a method using potassium ferrocyanide in acetic acid that demonstrates melanins as a deep green color; lipofuscins and heme pigments are unreactive.- Lillie sulfuric acid Nile blue s. a technique for showing fatty acid s when present in high concentrations.- Lison-Dunn s. a technique using leuco patent blue V and hydrogen peroxidase to demonstrate hemoglobin peroxidase on time sections and smears.- Loeffler s. a s. for flagella; the specimen is treated with a mixture of ferrous sulfate, tannic acid, and alcoholic fuchsin, then stained with aniline-water fuchsin or gentian violet made alkaline with sodium hydroxide solution.- Loeffler caustic s. a s. for flagella, utilizing an aqueous solution of tannin and ferrous sulfate with the addition of an alcoholic fuchsin s..- Luna-Ishak s. a staining method using celestine blue and acid fuchsin in which bile canaliculi s. pink to red.- Macchiavello s. a basic fuchsin-citric acid-methylene blue sequence in smears which produces red staining of rickettsiae and inclusion bodies, with nuclei staining blue.- MacNeal tetrachrome blood s. a s. for blood smears composed of a mixture of methylene blue, azure A, methylene violet, and eosin Y.- malarial pigment s. a s. using phloxine-toluidine blue O sequence; malarial pigment and nuclei are bluish, erythrocytes and cytoplasm are red to orange; found in phagocytic cells of the reticuloendothelial system.- Maldonado-San Jose s. a staining method for staining pancreatic islet cells, using a phloxine-azure B-hematoxylin sequence; alpha cells are purple, beta cells are violet-blue, delta cells are light blue, and exocrine cells are grayish blue with red secretion granules.- Mallory s. for actinomyces a s. using alum hematoxylin, followed by eosin; immersion in Ehrlich aniline crystal violet s., and Weigert iodine solution; mycelia s. blue and clubs s. red.- Mallory collagen s. one of a number of staining methods using phosphomolybdic or phosphotungstic acid with an acid s., such as aniline blue, or with hematoxylin for connective tissue staining.- Mallory s. for hemofuchsin sections are stained sequentially in alum hematoxylin and basic fuchsin; the lipofuchsin-like pigment and ceroid s. bright red, nuclei s. blue, while melanin and hemosiderin appear unstained in their natural browns.- Mallory iodine s. amyloid appears red-brown after Gram iodine, then violet and blue after flooding with dilute sulfuric acid.- Mallory phloxine s. a technique based on retention of phloxine by hyaline after overstaining and then decolorizing with lithium carbonate, used in combination with alum hematoxylin to give nuclear staining; hyaline appears red, older hyaline is pink to colorless, amyloid is pale pink, and nuclei are blue-black.- Mallory trichrome s. a method especially suitable for studying connective tissue; sections are stained in acid fuchsin, aniline blue -orange G solution, and phosphotungstic acid; fibrils of collagen are blue, fibroglia, neuroglia, and muscle fibers are red, and fibrils of elastin are pink or yellow. SYN: Mallory aniline blue s., Mallory triple s..- Mann methyl blue -eosin s. a s. useful for anterior pituitary and viral inclusion bodies; a mixture of the two dyes stains alpha cell granules red, beta cell granules dark blue, chromophobes gray to pink, colloid red, erythrocytes orange-red, and collagen fibers blue; this method is also useful for enterochromaffin, goblet, Paneth, and pancreatic islet cells; Negri bodies appear red while their nuclei and central granules are blue.- Marchi s. a staining method in which the specimen is hardened for 8–10 days in a modified Müller fixative, followed by immersion for 1–3 weeks in the same with the addition of osmic acid; fat and degenerating nerve fibers s. black.- Masson argentaffin s. a s. used to s. enterochromaffin granules brown-black.- Masson-Fontana ammoniac silver s. a s. used to demonstrate melanin and argentaffin granules. SYN: Fontana-Masson silver s..- Masson trichrome s. original composition for multicolored tissue preparations including ponceau de xylidine, acid fuchsin, iron alum hematoxylin, and either aniline blue or fast green FCF; chromatin stains black, cytoplasm is in shades of red, granules of eosinophils and mast cells are deep red, erythrocytes are black, elastic fibers are red, and collagen fibers and mucus are dark blue (aniline blue) or green (fast green FCF); modifications substitute other dyes, such as Biebrich scarlet red and wool green s..- Maximow s. for bone marrow an alum-hematoxylin and azure II-eosin s. used to distinguish granulated leukocytes, mast cells, and cartilage.- May-Grünwald s. a German equivalent of Jenner s., used for blood staining and in cytology; often used in combination with Giemsa s.; valuable in demonstrating parasitic flagellates.- metachromatic s. a s., such as methylene blue, thionin, or azure A, that has the ability to produce different colors with various histologic or cytologic structures.- methyl green -pyronin s. a staining method useful for identification of plasma cells which are intensely pyroninophilic; a mixture of a green and a red dye that has the property of staining highly polymerized nucleic acid (DNA) green and low molecular weight nucleic acid s (RNA) red. See Unna-Pappenheim s..- modified acid-fast s. a s. for coccidia (Cryptosporidium, Cyclospora, Isospora) in which the decolorizer is a very dilute acid (1–3% sulfuric acid); less likely to remove too much dye.- modified trichrome s. a s. developed from the Wheatley modification of the Gomori trichrome s. using 10 times the amount of chromotrope 2R dye for microsporidian spores, which s. pink to red.- MSB trichrome s. a s. for fibrin using martius yellow, brilliant crystal scarlet 6R, and soluble blue; fibrin is selectively stained red and connective tissue appears blue.- multiple s. a mixture of several dyes each having an independent selective action on one or more portions of the tissue.- Nair buffered methylene blue s. s. used to show nuclear detail of protozoan trophozoites when used at low pH (3.6–4.8).- Nakanishi s. a method for vital staining of bacteria in which a slide is treated with hot methylene blue solution until it acquires a sky-blue color, after which a drop of an emulsion of the bacteria is put on the cover glass and the latter laid on the slide; the bacteria are stained differentially, some parts more intensely than others.- Nauta s. a s. for degenerating axons in which they s. with silver and appear as fragmented and swollen fibers.- negative s. s. forming an opaque or colored background against which the object to be demonstrated appears as a translucent or colorless area; in electron microscopy, an electron opaque material, such as phosphotungstic acid or sodium phosphotungstate, is used to give detail as to surface structure.- Neisser s. a s. for the polar nuclei of the diphtheria bacillus which uses a mixture of methylene blue and crystal violet.- neutral s. a compound of an acid s. and a basic s., such as the eosinate of methylene blue, in which the anion and cation each contains a chromophore group. SYN: salt dye.- Nicolle s. for capsules s. in a mixture of a saturated solution of gentian violet in alcohol-phenol.- ninhydrin-Schiff s. for proteins proteins are revealed by using ninhydrin or alloxan to produce aldehydes from primary aliphatic amines by oxidative deamination; the aldehydes are shown by reaction with Schiff reagent.- Nissl s. 1. a method for staining nerve cells with basic fuchsin; 2. a method for staining aggregates of rough endoplasmic reticulum and ribosomes in neuronal cell bodies and dendrites with basic dyes such as cresyl violet (or cresyl echt violet), thionine, toluidin blue O, or methylene blue.- Noble s. a basic fuchsin-orange G staining technique for detection of viral inclusion bodies in fixed tissues.- nuclear s. a s. for cell nuclei, usually based on the binding of a basic dye to DNA or nucleohistone.- Padykula-Herman s. for myosin ATPase a technique similar to that of Gomori nonspecific alkaline phosphatase s., except that incubation is carried out with ATP as the substrate at pH 9.4 in the absence of Mg2+; enzyme activity is demonstrated as blackened deposits in the A band of striated muscle sarcomeres; control tissue sections lacking substrate and containing sulfhydryl inhibitors are necessary.- Paget-Eccleston s. an aldehyde-thionin-PAS-orange G staining technique modified to identify seven different cell types in the anterior pituitary gland.- panoptic s. a s. in which a Romanowsky-type s. is combined with another s.; such a combination improves the staining of cytoplasmic granules and other bodies.- Papanicolaou s. a multichromatic s. used principally on exfoliated cytologic specimens and based on aqueous hematoxylin with multiple counterstaining dyes in 95% ethyl alcohol, giving great transparency and delicacy of detail; important in cancer screening, especially of gynecologic smears.- Pappenheim s. a methyl green -pyronin s., originally used as a s. for lymphocytes.- paracarmine s. a staining fluid consisting of a solution of calcium chloride and carminic acid in 75% alcohol.- PAS s. SYN: periodic acid -Schiff s..- periodic acid -Schiff s. (PAS) a tissue-staining procedure in which 1,2-glycol groupings are first oxidized with periodic acid to aldehydes, which then react with the sulfite leucofuchsin reagent of Schiff, and become colored red-violet; strong staining occurs with polysaccharides, such as glycogen, and mucopolysaccharides of epithelial mucins, basement membranes, and connective tissue. SYN: PAS s..- Perls Prussian blue s. a s. for ferric iron as in hemosiderins, using potassium ferrocyanide in acetic acid or dilute hydrochloric acid followed by a red counterstain such as safranin O or neutral red; various hemosiderins and most mineral irons give a blue-green reaction, while nuclei s. red.- peroxidase s. a method for demonstrating peroxidase granules in some neutrophils and in eosinophils; the enzyme promotes the oxidation of benzidine by hydrogen peroxide; tissues treated with horseradish peroxidase can also have the enzyme detected in the electron microscope.- phosphotungstic acid s. the first general s. used for electron microscopy; a selective s. for extracellular components such as elastin, collagen, and basement membrane mucopolysaccharides; it can be followed by uranyl acetate or lead. SYN: PTA s..- picrocarmine s. a red crystalline powder derived from a solution of carmine, ammonia, and picric acid, which is evaporated, leaving the powder (soluble in water); it produces excellent staining of keratohyaline granules.- picro-Mallory trichrome s. a modification of Mallory trichrome s. that involves the addition of picric acid.- plastic section s. 1. for electron microscopy, a s. ( e.g., osmic acid, PTA, potassium permanganate) used on thin sections of plastic-embedded tissues, utilizing differential attachment of heavy atoms to various cellular and tissue structures so that electrons will be absorbed and scattered by these structures to produce an image; to achieve differential staining, the s. must penetrate nonwettable plastic embedments; 2. for light microscopy, a s. ( e.g., alkaline toluidine blue, silver methenamine) used on plastic-embedded tissues to attain higher resolution and more detail than normally possible; semi-thick (0.5-1.5 μm) sections are particularly useful in renal pathology, especially in combination with the phase microscope.- port-wine s. SYN: nevus flammeus.- positive s. direct binding of a dye with a tissue component to produce contrast; in electron microscopy, heavy metals like uranyl and lead salts are used to bind to selective cell constituents to produce increased density to the electron beam, i.e., contrast.- Prussian blue s. a s. employing acid potassium ferrocyanide to demonstrate iron, as in siderocytes.- PTA s. SYN: phosphotungstic acid s..- Puchtler-Sweat s. for basement membranes a staining method using resorcin-fuchsin and nuclear fast red solutions after Carnoy fixative; basement membranes are gray to black and nuclei pink to red.- Puchtler-Sweat s. for hemoglobin and hemosiderin a complex staining method in which, on a yellow background, hemoglobin is stained red, hemosiderin blue to green, and elastic fibers pink.- Q-banding s. a fluorescent s. for chromosomes which produces specific banding patterns for each pair of homologous chromosomes; the acridine dye derivative, quinacrine hydrochloride, or other derivatives like quinacrine mustard dihydrochloride produces a green-yellow fluorescence at pH 4.5 in chromosome segments rich in constitutive heterochromatin with deoxyadenylate-deoxythymidilate (A-T) bases of DNA; centromeric regions of human chromosomes 3, 4, and 13 are specifically stained, as are satellites of some acrocentric chromosomes and the end of the long arm of the Y chromosome; banding patterns are similar to those obtained with G-banding s.; similar fluorescent s. results are seen with the antibiotics adriamycin and daunomycin, as well as the tertiary dyes butyl proflavine and dapi, and the bisbenzimidazole dye hoechst 33258. SYN: quinacrine chromosome banding s..- Rambourg chromic acid -phosphotungstic acid s. a s. for glycoproteins, used with an electron microscope, with which ultrathin tissue sections reveal complex carbohydrates in the same locations as shown by Rambourg periodic acid -chromic methenamine-silver s..- Rambourg periodic acid -chromic methenamine-silver s. a s. for glycoproteins, used with an electron microscope, adapted from the Gomori-Jones periodic acid -methenamine-silver s.; it produces silver deposits in mature saccules of the Golgi apparatus, lysosomal vesicles, cell coat, and basement membranes.- R-banding s. a reverse Giemsa chromosome banding method that produces bands complementary to G-bands; induced by treatment with high temperature, low pH, or acridine orange staining; often used together with G-banding on human karyotype to determine whether there are deletions.- Romanowsky blood s. prototype of the eosin-methylene blue stains for blood smears, using aqueous solutions made of a mixture of methylene blue (saturated) and eosin. Romanowsky-type stains depend for their action on compounds formed by interaction of methylene blue and eosin; most are of no value if water is present in the alcohol because neutral dyes become precipitated.- Roux s. a double s. for diphtheria bacilli which employs crystal violet or dahlia and methyl green.- Ryan s. a modified trichrome s. for microsporidian spores in which the chromotrope 2R is 10 times the normal concentration used in trichrome stains for stool specimens and the counterstain is aniline blue.- Schaeffer-Fulton s. a s. for bacterial spores using malachite green and safranin so that bacterial bodies are red to pink and spores are green.- Schmorl ferric-ferricyanide reduction s. a s. to test for reducing substances in tissues, including melanin, argentaffin granules, thyroid colloid, keratin, keratohyalin, and lipofuscin pigments; ferricyanide is converted into ferrocyanide which is converted to insoluble Prussian blue in the presence of ferric ions.- Schmorl picrothionin s. a s. for compact bone which employs thionin and picric acid solutions to produce blue to blue-black staining of bone canaliculi and cells; bone matrix is yellowish and cartilage ground substance is purple.- Schultz s. a s. for cholesterol; a relatively specific but insensitive histochemical test for cholesterol and cholesterol esters in which frozen sections of formalin-fixed tissues are oxidized in iron alum, hydrogen peroxide, or sodium iodate, then treated with sulfuric acid to give a blue-green to red color in a positive reaction; the presence of glycerol inhibits the reaction.- selective s. a s. that colors one portion of a tissue or cell exclusively or more deeply than the remaining portions.- silver s. any of a variety of stains ( e.g., Bielschowsky, Gomori silver, impregnation stains) which employ alkaline silver nitrate solutions to s. connective tissue fibers (reticulin, collagen), calcium salt deposits, spirochaetes, neurological tissue, and nucleolar organizer regions.- silver-ammoniac silver s. a s. for the acid protein component of nucleolar regions that are active or that were transcriptionally active in the preceding interphase; uses silver nitrate, ammoniacal silver, and formalin. SYN: Ag-AS s..- silver protein s. a silver proteinate complex used in staining nerve fibers, nerve endings, and flagellate protozoa; also used to demonstrate phagocytosis in living animals by the cells of the reticuloendothelial system.- supravital s. a procedure in which living tissue is removed from the body and cells are placed in a nontoxic dye solution so that their vital processes may be studied.- Takayama s. a s. containing pyridine, sodium hydrate, and dextrose; used for identification of blood stains; a drop added to a suspected blood s. results in the formation of hemochromogen crystals.- telomeric R-banding s. a modified R-banding s. in which the telomeres become strongly stained and faint R-banding still occurs over the rest of the chromosomes; uses air-dried slides, aging for several days, and staining in hot phosphate-buffered Giemsa s..- thioflavine T s. a s. employed to detect amyloid, which induces specific yellow fluorescence; tissue sections are first put in alum-hematoxylin to quench nuclear fluorescence and then stained in thioflavine T.- Tizzoni s. a s. used as a test for iron in tissue; the tissue is treated with a solution of potassium ferrocyanide and then with dilute hydrochloric acid; a blue coloration indicates the presence of iron.- Toison s. a blood diluent and leukocyte s. containing methyl violet, sodium chloride, sodium sulfate, and glycerin; also used for erythrocyte counts.- trichrome s. staining combinations that usually contain three dyes of contrasting colors selected to s. connective tissue, muscle, cytoplasm, and nuclei in bright colors; generally, tissue sections are first dyed in iron hematoxylin before being treated with the other dyes.- ultrafast Pap s. a modified Papanicolaou s. suitable for use in situations in which rapid decisions are essential and frozen sections may not be sufficiently reliable or practical. SEE ALSO: Papanicolaou s..- Unna s. 1. an alkaline methylene blue s. for plasma cells; 2. a polychrome methylene blue s. with which mast cells are stained red (metachromatic).- Unna-Pappenheim s. a contrast s. consisting of a methyl green -pyronin solution; originally used for gonococci, but later used to detect RNA and DNA in tissue sections; RNA is stained red and DNA appears green; used to demonstrate plasma cells during chronic inflammation. See methyl green -pyronin s..- uranyl acetate s. a s. used in electron microscopy; uranyl acetate binds specifically to nucleic acid s but selectively tends to be abolished by osmium fixation; proteins are well-stained, but cytomembranes are poorly stained.- urate crystals s. a s. using silver methenamine to detect crystals, which polarize light in contrast with calcium crystals; useful in diagnosing gout and kidney infarcts resulting from uric acid build-up.- van Ermengen s. a method for staining flagella that uses glacial acetic acid, osmic acid, tannic acid, silver nitrate, gallic acid, and potassium acetate.- van Gieson s. a mixture of acid fuchsin in saturated picric acid solution, used in collagen staining.- Verhoeff elastic tissue s. a s. for tissue sections in which a mixture of hematoxylin, ferric chloride, and Lugol iodine solution is used; tissue may be counterstained, if desired, with eosin or van Gieson s.; elastic fibers and nuclei appear blue-black to black while collagen and other components are shades of pink to red.- vital s. a s. applied to cells or parts of cells while they are still living.- von Kossa s. a s. for calcium in mineralized tissue, utilizing a silver nitrate solution followed by sodium thiosulfate; calcified bone but not osteoid is stained brown to black. SYN: Kossa s..- Wachstein-Meissel s. for calcium-magnesium-ATPase a method similar to that of Gomori nonspecific acid phosphatase s., except that incubation is carried out with ATP as substrate at neutral pH; enzyme activity is generally demonstrated at cell membranes.- Warthin-Starry silver s. a s. for spirochetes in which preparations are incubated in 1% silver nitrate solution followed by a developer.- Weber s. a modified trichrome s. for microsporidian spores in which the chromotrope 2R is 10 times the normal concentration used in trichrome stains for stool specimens and the counterstain is fast green.- Weigert s. for actinomyces a staining method using immersion in a dark red orsellin solution in alcohol, then staining in crystal-violet solution. SEE ALSO: iron hematoxylin.- Weigert s. for elastin a staining solution of fuchsin, resorcin, and ferric chloride; elastic fibers s. blue-black.- Weigert s. for fibrin a staining method using solutions of aniline-crystal violet and iodine-potassium iodide, then decolorizing in aniline oil and xylol; the fibrin is stained dark blue.- Weigert-Gram s. a s. for bacteria in tissues in which sections are stained in alum-hematoxylin, then in eosin, aniline methyl violet, and Lugol solution.- Weigert iron hematoxylin s. a nuclear staining solution containing hematoxylin, ferric chloride, and hydrochloric acid; useful in combination with van Gieson s., especially for demonstrating connective tissue elements or Entamoeba histolytica in sections.- Weigert s. for myelin a staining method using ferric chloride and hematoxylin; myelin stains deep blue, degenerated portions a light yellowish color.- Weigert s. for neuroglia a complicated process in which the final treatment is like that for staining fibrin; neuroglia and nuclei s. blue.- Wilder s. for reticulum a silver impregnation technique in which reticulum appears as black, well-defined fibers without beading and with a relatively clear background.- Williams s. a s. for Negri bodies that uses picric acid, fuchsin, and methylene blue; Negri bodies are magenta, granules and nerve cells blue, and erythrocytes yellowish.- Wright s. a staining mixture of eosinates of polychromed methylene blue used in staining of blood smears.- Ziehl s. a carbol-fuchsin solution of phenol and basic fuchsin used to demonstrate bacteria and cell nuclei.- Ziehl-Neelsen s. a method for staining acid-fast bacteria using Ziehl s., decolorizing in acid alcohol, and counterstaining with methylene blue; acid-fast organisms appear red, other tissue elements light blue; a modification of this s. is also used for Actinomycetes and Brucella.
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stain 'stān vt1) to cause discoloration of <smoking \stains teeth>2) to color by processes affecting chemically or otherwise the material itself <\stain bacteria with a fluorescent dye> vi to receive a stainstain n2) a preparation (as of dye or pigment) used in staining something esp a dye or mixture of dyes used in microscopy to make minute and transparent structures visible, to differentiate tissue elements, or to produce specific chemical reactions* * *
1. n. a dye used to colour tissues and other specimens for microscopical examination. In an acid stain the colour is carried by an acid radical and the stain is taken up by parts of the specimen having a basic (alkaline) reaction. In a basic stain the colour, carried by a basic radical, is attracted to parts of the specimen having an acidic reaction. Neutral stains have neither acidic nor basic affinities. A contrast stain is used to give colour to parts of a tissue not affected by a previously applied stain. A differential stain allows different elements in a specimen to be distinguished by staining them in different colours.2. vb. to treat a specimen for microscopical study with a stain.* * *
(stān) 1. any dye, reagent, or other material used in producing coloration, such as a substance used in coloring tissues or microorganisms for microscopical study. For specific stains, see Stains and Staining Methods below. 2. a superficial discoloration, or an artificially colored spot in the skin.Listing some of the preparations and methods commonly employed in histologic and pathologic technique (arranged alphabetically). For other stains, see under blue, red, etc.
Medical dictionary. 2011.
