periodic acid-Schiff stain

(redirected from Periodic acid Schiff)

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


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.

per·i·od·ic ac·id-Schiff stain

(PAS) (pērē-odik asid shif stān)
A clinical tissue-staining procedure.
References in periodicals archive ?
The Cellular Pathology Department of South Devon NHS Foundation Trust has a requirement to replace it~s existing separate stainer and separate coverslipper with an integrated system capable of performing the existing repertoire of stains which are Haeamtoxylin and Eosin (H&E), Papanicolaou (PAP), Alcian blue Periodic Acid Schiff (ABP), Periodic Acid Schiff (PAS) and a modified Giemsa for helicobacter within the one unit.
Cytochemically, these cells were negative for myeloperoxidase, Sudan black, acid phosphatase and periodic acid Schiff, while few cells showed granular and dot positivity with non-specific esterase as described in an older literature [5].
Tissue samples were processed routinely, sectioned, mounted on glass slides, and stained with hematoxylin and eosin or periodic acid Schiff (PAS) for light microscopic examination.
Periodic Acid Schiff staining was negative for fungal infections.
8] Moreover, the presence of the acidophilic granules gives the tumor cells a foamy appearance [9] and a diastase-resistance periodic acid Schiff reaction.