Use of tris-buffer-fortified thionine-SO2 for detection of DNA-aldehyde following Feulgen procedure.

This communication presents informations on the use of tris-buffer along with N HCl and potassium metabisulphite for the preparation of thionine-SO2 in staining DNA-aldehyde molecules of acid hydrolysed mammalian liver sections. It has been found that thionine, containing tris-buffer, N HCl and potassium metabisulphite, stains DNA-aldehyde molecules with better result than is possible with the control dye-SO2 reagent that does not contain this buffer. The absorption spectra of nuclei stained with this dye-reagent prepared with tris-buffer have also been presented. Further, it has been found that nuclei stained with the freshly prepared dye-SO2 reagent is bluish-violet, whereas those stained with an old dye-reagent is sky blue in colour. The reason for the slightly enhanced nuclear colouration with the experimental dye-reagent over the control has been considered to be due to slightly increased pH in the former as compared with that of the latter. The mechanism of staining with thionine-SO2 has been considered to be of Feulgen type.