| PAS stain | <technique> A histochemical technique based on periodic acid oxidation of a substance containing the 1,2-glycol grouping. It is used for staining carbohydrates as the resulting dialdehyde reacts with Schiff reagent to form a coloured product. Substances that can be demonstrated include carbohydrates, mucins, cartilage matrix, collagen, reticulum, basement membranes, fibrin, thyroid colloid, amyloid, glomerular hyaline deposits, and a number of other secretions or tissue constituents. Also used in for staining gels on which glycoproteins have been run. See: periodic acid Schiff reaction Synonym: PAS stain. (22 Sep 2002) |
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| Kasten's fluorescent PAS stain | <technique> A fluorescent modification of the periodic acid Schiff stain for polysaccharides which uses one of Kasten's fluorescent Schiff reagents. (05 Mar 2000) |
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| PAS | <abbreviation> P-aminosalicylic acid; periodic acid-Schiff stain. (05 Mar 2000) |
| PAS gene | <genetics, molecular biology> Genes essential for the biogenesis and proliferation of peroxisomes in yeast (s. Cerevisiae). PAS1 codes for a rather hydrophilic 117 kD protein with two ATP binding sites and similarity with some ATPases, PAS2 codes for a 183 residue polypeptide that seems to be a member of the ubiquitin conjugating protein family, PAS3 codes for a 48 kD integral membrane protein that may be part of the import machinery. (18 Nov 1997) |
| Abbott's stain | <technique> Spores are stained blue with alkaline methylene blue; bodies of the bacilli become pink with eosin counterstain. (05 Mar 2000) |
| aceto-orcein stain | <technique> A stain used for chromosomes in air-dried or squashed cytologic material. (05 Mar 2000) |
| acid-fast stain | <technique> A staining technique used to determine the cell wall property of a microorganism. After stained with dye such as hot carbolfuschin, an acid-fast organism, (for example Mycobacterium species) will retain the colour in its cell wall after being washed with acid-alcohol. (13 Nov 1997) |
| acid stain | <technique> A dye in which the anion is the coloured component of the dye molecule, e.g., sodium eosinate (eosin). (05 Mar 2000) |
| Ag-AS stain | <technique> A stain for the acid protein component of nucleolar regions which are active or which were transcriptionally active in the preceding interphase; uses silver nitrate, ammoniacal silver, and formalin. Synonym: Ag-AS stain. (05 Mar 2000) |
| Albert's stain | <technique> A stain for diphtheria bacilli and their metachromatic granules; contains toluidine blue, methyl green, glacial acetic acid, alcohol, and distilled water. (05 Mar 2000) |
| Altmann's anilin-acid fuchsin stain | <technique> A mixture of picric acid, anilin, and acid fuchsin which stains mitochondria crimson against a yellow background. (05 Mar 2000) |
| auramine O fluorescent stain | <technique> A rapid and accurate technique for Mycobacterium tuberculosis, using auramine O-phenol and a methylene blue counterstain. (05 Mar 2000) |
| basic fuchsin-methylene blue stain | <technique> A stain for intact epoxy sections; semi-thick 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. (05 Mar 2000) |
| basic stain | <technique> A dye in which the cation is the coloured component of the dye molecule that binds to anionic groups of nucleic acids (PO4≡) or acidic mucopolysaccharides (e.g., chondroitin sulfate). (05 Mar 2000) |
| Bauer's chromic acid leucofuchsin stain | <technique> A stain for glycogen and fungi utilizing chromic acid as an oxidizing agent of polysaccharides, followed by Schiff's reagent; glycogen and fungi cell walls appear deep red. (05 Mar 2000) |
| Becker's stain | <technique> For spirochetes, a stain applied to thin films fixed in formaldehyde-acetic acid; preparations are treated successively with tannin, carbolic acid, and carbol fuchsin. (05 Mar 2000) |