periodic acid-Schiff stain

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per·i·od·ic ac·id-·Schiff stain (PAS),

a tissue-staining procedure in which 1,2-glycol groupings are first oxidized with periodic acid to aldehydes that then react with the sulfite leucofuchsin reagent of Schiff and turn red-violet; strong staining occurs with polysaccharides, such as glycogen, and mucopolysaccharides of epithelial mucins, basement membranes, and connective tissue.
Synonym(s): PAS stain
Farlex Partner Medical Dictionary © Farlex 2012


Hugo, German chemist in Florence, 1834-1915.
Kasten fluorescent Schiff reagents - see under Kasten
ninhydrin-Schiff stain for proteins
periodic acid-Schiff stain - a tissue-staining procedure. Synonym(s): PAS stain
Schiff base - condensation products of aldehydes and ketones with primary amine. Synonym(s): aldimine
Schiff reagent - used for aldehydes and in histochemistry to detect polysaccharides, DNA, and proteins.
Medical Eponyms © Farlex 2012

per·i·od·ic ac·id-Schiff stain

(PAS) (pērē-odik asid shif stān)
A clinical tissue-staining procedure.
Medical Dictionary for the Dental Professions © Farlex 2012
References in periodicals archive ?
The retinas were prepared with trypsin digestion and stained with periodic acid-Schiff stain. It was observed that endothelial cells proliferated (a).
The diagnosis of cylindroma was rendered on H&E stained histologic sections supplemented by an ancillary periodic acid-Schiff stain. While establishing this diagnosis was not particularly challenging in this well-oriented and completely resected tumor, it is possible that a smaller sampling of the tumor, such as a core biopsy, could have been misinterpreted as a basaloid-appearing primary breast neoplasm with a differential diagnosis potentially including basaloid forms of ductal carcinoma in situ, basaloid forms of solid/nested invasive ductal carcinoma, and adenoid cystic carcinoma.
Periodic acid-Schiff stain (original magnification X20) of goblet cells (arrow) in the epithelial component of the nevus.
More accurate histopathologic evaluation is possible with periodic acid-Schiff stain, immunofluorescent microscopy with calcofluor stain, or polymerase chain reaction, but these techniques are more expensive and less feasible in outpatient clinics.
On any body site, it is necessary to use a periodic acid-Schiff stain to rule out dermatophyte infection as a cause for spongiotic dermatitis.
insidiosum stains well with Gomori methenamine silver and periodic acid-Schiff stain. The organism appears with broad, branched, and sparsely septate or nonseptate hyphae, often identified as fungal elements of the zygomycetes (6).
(11) Typical cytoplasmic glycogen can be demonstrated on periodic acid-Schiff stain, whereas the muscle characteristics of the cells can be confirmed by strong positive reaction for desmin, muscle-specific actin, and myoglobin.
A periodic acid-Schiff stain indicated absence of glycogen deposits.
Periodic acid-Schiff stain failed to demonstrate glycogen particles in the cytoplasm of the cells.
Periodic acid-Schiff stain demonstrated the presence of positive granules in the cytoplasm of nucleated red blood cells and some blasts (Figure 2).
Mucicarmine stain was negative and periodic acid-Schiff stain was positive and seen decorating the cell membrane.

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