title: Demonstration of DNA with an extra-sensitive Schiff's reagent and a Schiff-type dye-reagent, toluidine blue O-SO2.
abstract: This paper describes a method for the preparation of Schiff's reagent as well as a Schiff-type dye-reagent, toluidine blue O-SO2 for use in Feulgen procedure. The method involves replacement of the usual N HCl by N H2SO4 and the usual amount of potassium metabisulphite. Following this method of preparation, an extra-sensitive Schiff's reagent is obtained which requires only 4-5 min for optimum nuclear colouration even when staining is performed at 5 degrees C. This Schiff's reagent produces perfect Feulgen staining up to 6 months after preparation. Toluidine blue O-SO2, prepared with N H2SO4 and potassium metabisulphite, also produces perfect Feulgen type staining of the DNA-aldehyde molecules of acid-hydrolysed mammalian tissue sections. Toluidine blue O-SO2 when shaken with activated charcoal and filtered produces very satisfactory result. The shell-life of this dye-reagent is just a week. The suitability of the use of N H2SO4 for the preparation of Schiff's reagent as well as a Schiff-type dye-reagent, toluidine blue O-SO2, has been discussed.
mesh_terms: D000818:Animals; D002606:Charcoal; D002875:Chromosomes / Q000648:ultrastructure; D004247:DNA / Q000032:analysis*; D006110:Grasshoppers; D008099:Liver / Q000032:analysis; D008297:Male; D051381:Rats; D013194:Staining and Labeling; D013438:Sulfhydryl Compounds; D013737:Testis / Q000648:ultrastructure; D014048:Tolonium Chloride
chemical_list: D013438:Sulfhydryl Compounds; D014048:Tolonium Chloride; D002606:Charcoal; D004247:DNA; C005732:thioacetic acid