acid-fast stain

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Related to acid-fast stain: Acid fast bacilli


1. a substance used to impart color to tissues or cells, to facilitate microscopic study and identification.
2. an area of discoloration of the skin.
acid-fast stain a staining procedure for demonstrating acid-fast microorganisms.
differential stain one that facilitates differentiation of various elements in a specimen.
endogenous stain an intrinsic stain acquired during tooth development.
exogenous stain an intrinsic stain acquired after a tooth has erupted.
extrinsic stain a stain that can be removed from a tooth surface by polishing.
Giemsa stain a solution containing azure II-eosin, azure II-glycerin, and methanol; used for staining protozoan parasites such as Plasmodium and Trypanosoma, for Chlamydia, for differential staining of blood smears, and for viral inclusion bodies. Stained elements appear pink to purple to blue.
Gram stain a staining procedure in which bacteria are stained with crystal violet, treated with strong iodine solution, decolorized with ethanol or ethanol-acetone, and counterstained with a contrasting dye; those retaining the stain are called gram-positive, and those losing the stain but staining with the counterstain are called gram-negative.
hematoxylin and eosin stain a mixture of hematoxylin in distilled water and aqueous eosin solution, employed universally for routine examination of tissues.
intrinsic stain a stain that is within the enamel of a tooth and cannot be removed by polishing.
metachromatic stain one that produces in certain elements a color different from that of the stain itself.
nuclear stain one that selectively stains cell nuclei, generally a basic stain.
port-wine stain a persistent dark red to purple nevus flammeus that grows proportionately with the affected child and is usually found on the face. Initially it is macular, but the surface may develop angiomatous overgrowths with time. Port-wine stains often occur in association with other congenital abnormalities.
supravital stain a stain introduced in living tissue or cells that have been removed from the body.
tumor stain an area of increased density in a radiograph, due to collection of contrast material in distorted and abnormal vessels, prominent in the capillary and venous phases of arteriography, and presumed to indicate neoplasm.
vital stain a stain introduced into the living organism, and taken up selectively by various tissue or cellular elements.
Wright's stain a mixture of eosin and methylene blue, used for demonstrating blood cells and malarial parasites.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

acid-fast stain

A generic term for any of a number of special histologic stains—Ziehl-Neelsen, Kinyoun, hot carbolfuschin, et al—used to identify Mycobacterium spp,

Although there are other, non-pathogenic species of mycobacteria—which also stain with the acid fast technique present in normal flora—in the appropriate setting and in view of the increased prevalence of persons with immunosuppressed states, a positive acid-fast stain is presumptive evidence that the person has tuberculosis. Myocobacteria are acid-fast due to the mycolic acid content in the outer capsule; at an increased temperature, the basic fuchsin in phenol penetrates the capsular wax, hardens, and retains the dye during treatment with acid alcohol. Acid-fast stains may adhere to free hydroxy and carboxi- group of mycolic acid, explaining the acid-fastness of pine pollen, keratohyaline, lead inclusions, histoplasmosis, and lipofuchsin, as well as Nocardia spp and certain propionic bacteria. The Fite AFS uses a xylene-oil combination to partially ‘restore’ the acid-fastness lost in routine processing and is used to identify Mycobacterium leprae.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.

acid-fast stain

Microbiology A generic term for any of a number of special histologic stains–Ziehl-Neelsen, Kinyoun, hot carbolfuschin, et al, used to identify Mycobacterium spp
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.

Acid-fast stain

A special stain done to microscopically identify the bacteria that cause tuberculosis.
Mentioned in: Sputum Culture
Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
Distribution of tuberculosis cases according to site, skin test reaction and microbiological analysis (Lowestein-Jensen culture and Acid-Fast stain).
Worldwide, most clinical laboratories had not been looking for this organism because it is found only when specific tests (e.g., a modified acid-fast stain) are performed on stool specimens.
Five cases presented with epithelioid granuloma with caseous necrosis with or without positive acid-fast stain; four cases presented with epithelioid granuloma with positive acid-fast stain; two cases presented with chronic inflammation with positive acid-fast stain; 19 cases presented with epithelioid granuloma without positive acid-fast stain; 44 cases presented with chronic inflammation.
With the acid-fast stain, these illnesses would be misidentified as TB and, in most instances, also would be reported as treatment failures.
Morphologic characteristics, together with negative routine acid-fast stains (Ziehl-Neelsen, auramine-rhodamine), differentiate nocardia from mycobacteria.
However, with the modified acid-fast stain, CLB may stain deep mottled red or pink; some resist staining and appear as glassy, membranous cysts.
Microscopic examination of the acid-fast stained fecal smear revealed ovoid oocysts that were an average size of 7.5-9.8 x 5.5-7.0 [micro] m (Figure 1).
parvum oocysts were processed with acid-fast stain (AFS) (8) to check for normal cellular morphologic features.
Although more sensitive than culture and acid-fast stains in diagnosing intestinal TB [18], recent data reported lower negative prediction and variable specificity in extrapulmonary TB [19, 20].
Use of modified acid-fast stains, such as Kinyoun stain, also improves visualization [12].
These reactions were initially believed to be aseptic, hypersensitivity responses given that organisms could rarely be cultured or identified with acid-fast stains of the affected tissue [9].
To confirm the presence of acid-fast bacteria, tissue sections were stained using multiple commercially available acid-fast stains (Fite's Stain Kit, American Master Tech Scientific Laboratory Supplies, Lodi, California; Kinyoun's Stain, Gibson Labs, Lexington, Kentucky; Ziehl-Neelsen Stain, Gibson Labs, Lexington, Kentucky).