Periodic acid Schiff reagent

Periodic acid-Schiff reagent Detects glycoproteins as pink bands after electrophoretic separation. 

The band number refers to the position of migration on SDS-PAGE (see Figure 52-3). The glycophorins are detected by staining with the periodic acid-Schiff reagent. A number of other components (eg, 42 and 4.9) are not listed. Native spectrin is... 

Figure 11. Polyacrylamide disc gel electrophoretic patterns of extracellular proteins produced by T. reesei QM 9414. The sample applied to the gel on the left was 130 fig extracellular protein from T. reesei my-celia grown on 1% Avicel (29), that applied to the gel on the right was 120 fig extracellular protein produced from sophorose-incubated mycelia. The bands shown here were stained for protein with Coomassie Blue and could, in all cases, also be stained for carbohydrate with the periodic acid-Schiff reagent.

For glyco- and mucoproteins the usual reagent is periodic acid-Schiff reagent (abbreviated PAS). This method was initiated by Koiw and Gronwall (K14) in 1952. Quantities of protein about four times as large as usual are applied to the paper (G19, K15, K16, S15). 

Fig. 1.—A Cross-section of the Outer Part of a Seed of Trigonella foenum-graecum Before Mobilization of the Galactomannan, Showing the Three-layered Seed-coat (S) and a Small Part of the Cotyledon (C), with the Endosperm in Between. [The aleurone layer (A) is the outer cell-layer of the endosperm, and the rest of the endosperm is composed of large cells that have thin, primary walls and are completely filled with the dark-stained galactomannan (G). Stained with the periodic acid-Schiff reagent x300 (reproduced, by permission, from Ref. 199).]...

Histochemical techniques for detecting substrate before and after enzyme treatment are extremely useful in studies on cellular structure. One of the oldest histochemical tests utilized saliva to identify suspected glycogen or starch. More definitive results are obtained when thin sections of a tissue are incubated in a buffered solution of purified amylase and stained for poly-utc-glycols. Material stained by periodic acid-Schiff reagent in the control, but not in the section exposed to amylase, is assumed to be glycogen or starch. Two more of the numerous histochemical techniques associated with localization of substrate are—using hya-luronidase to locate hyaluronic acid and chondroitin 4- and 6-sulfates (179) and using neuraminidases to locate sialomucins (180). By use of electron microscopy in combination with the histochemical technique subcellular localization can be obtained. 

PAS Periodic acid-Schiff reagent PBA Polyclonal B cell activators PBC Primary biliary cirrhosis PBL Peripheral blood lymphocytes PBMC Peripheral blood mononuclear cells PBN N-tert-butyl-a-phenylnitrone PBS Phosphate-buffered saline PC Phosphatidylcholine... 

Solubilization of erythrocyte ghosts in 1 % sodium dodecyl sulfate, followed by SDS-polyacrylamine gel electrophoresis and staining with Coomassie blue reveals more than 10 well defined protein bands. When staining is performed with periodic acid-Schiff reagent (PAS), which stains carbohydrates, four bands (PAS bands) are revealed. 

Lipoproteins can be localized on gels by staining either for protein or lipid moieties. Proteins are stained with Coomassie blue, although the lipoproteins should be free from plasma proteins before separation. Quantitation is achieved by densitometry. Lipids can be stained with oil red O and in this case plasma proteins do not interfere. Other stains can also be used, such as periodic acid-Schiff reagent for carbohydrate moieties. If the lipoproteins are radioactively labelled they can also be visualized on film by autoradiography. Immunoblotting can be used for the localization of specific apolipoproteins if suitable antibodies are available. 

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