title: Shelf-life of citric acid-toluidine blue O-SO2 and its influence on Feulgen staining.
abstract: The paper reports on the preparation of a dye-SO2 reagent employing a Schiff-type dye, toluidine blue O. The method is to replace 5 ml of N HCl per 100 ml of the dye solution by citric acid. The usual potassium metabisulphite is then added. The pH of this new modified dye-SO2 reagent is 2.5 as against 1.6 for the hydrochloric acid-toluidine blue O-SO2. The shelf-life of this newly developed dye-SO2 reagent is four weeks with appreciable reduction of staining intensity after this period as compared with that of a freshly prepared dye-reagent with N HCl. A possible interpretation for the observed phenomenon has been suggested.
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000032:analysis; D002951:Citrates; D004247:DNA / Q000032:analysis*; D004355:Drug Stability; D008099:Liver / Q000032:analysis; D051381:Rats; D013194:Staining and Labeling / Q000379:methods*; D013447:Sulfites; D014048:Tolonium Chloride
chemical_list: D002951:Citrates; D013447:Sulfites; D014048:Tolonium Chloride; D004247:DNA