What does PAS staining indicate?
What does PAS staining indicate?
Periodic acid–Schiff (PAS) is a staining method used to detect polysaccharides such as glycogen, and mucosubstances such as glycoproteins, glycolipids and mucins in tissues. A suitable basic stain is often used as a counterstain.
What cells would PAS stain?
Germ Cell Neoplasms of the Ovary Periodic acid–Schiff (PAS) stain highlights the abundant glycogen in the tumor cells; the staining will disappear after diastase treatment. By immunohistochemistry, dysgerminoma cells are positive for PLAP (strong, cytoplasmic staining), SALL4, CD117, and OCT4 (Fig. 16.7).
What stains positive with PAS?
Periodic acid–Schiff (PAS)–diastase. PAS stains both glycogen and α1-AT globules a dark, reddish-purple, and diastase digests the glycogen. Thus, when a PAS-diastase stain is used, the glycogen has been removed by the diastase, and the only positively staining globules are those due to α1-AT.
What is the basic principle of PAS stain?
PRINCIPLE: The PAS stain is a histochemical reaction in that the periodic acid oxidizes the carbon to carbon bond forming aldehydes which react to the fuchsin-sulfurous acid which form the magenta color.
What does PAS stain in fungi?
The PAS stain is a simple stain that demonstrates polysaccharides. Cellulose and chitin, two substances rich in polysaccharides, are found in the cell walls of fungi. The addition of the enzyme diastase (PASd) eliminates the potential of confounding results caused by the presence of glycogen.
What is PAS and PAS-D?
Abstract. Periodic Acid-Schiff (PAS) with diastase (PAS-D) refers to the use of the PAS stain in combination with diastase, which is an enzyme that digests the glycogen. The purpose of using the PAS-D procedure is to differentiate glycogen from other PAS-positive elements in tissue samples.
What are the procedures in performing PAS staining?
Procedure:
- Deparaffinize and hydrate to water.
- Oxidize in 0.5% periodic acid solution for 5 minutes.
- Rinse in distilled water.
- Place in Schiff reagent for 15 minutes (Sections become light pink color during this step).
- Wash in lukewarm tap water for 5 minutes (Immediately sections turn dark pink color).
How do you do PAS staining?
Procedure:
- Deparaffinize and hydrate to water.
- Oxidize in 0.5% periodic acid solution for 5 minutes.
- Rinse in distilled water.
- Place in Schiff reagent for 15 minutes (Sections become light pink color during this step).
- Wash in lukewarm tap water for 5 minutes (Immediately sections turn dark pink color).
What is PAS stain used for in microbiology?
Esophageal candidiasis, PAS stain Liver in glycogen storage disease, PAS stain PAS staining is mainly used for staining structures containing a high proportion of carbohydrate macromolecules (glycogen, glycoprotein, proteoglycans), typically found in e.g. connective tissues, mucus, the glycocalyx, and basal laminae.
What does Pas stand for?
Periodic acid–Schiff ( PAS) is a staining method used to detect polysaccharides such as glycogen, and mucosubstances such as glycoproteins, glycolipids and mucins in tissues. The reaction of periodic acid oxidizes the vicinal diols in these sugars, usually breaking up the bond between two adjacent carbons not…
What is the difference between PAS diastase stain and PAS-D?
These aldehydes then react with the Schiff reagent to give a purple-magenta color. A suitable basic stain is often used as a counterstain. • PAS diastase stain (PAS-D) is PAS stain used in combination with diastase, an enzyme that breaks down glycogen. • Alcian blue/periodic acid–Schiff (AB/PAS or AB-PAS) uses alcian blue before the PAS step.
Why are bacterial stains used to stain cells?
This is because of the lack of contrast coupled with the small size of the bacterial cell. The use of stains that react chemically with cell material will enhance the contrast between the cell and the background. A stain is a dye consisting of a colored ion (a chromophore) and a counter ion to balance the charge.
