PERMANENT FEULGEN STAINING PREPARATION WITHOUT MOUNTING MEDIUM USE

Abstract. Introduction. Feulgen staining is used in medical and biological studies when it is necessary to assess the level of DNA and its localization in cells. Some fixatives, mounting media and light can decrease the quality of preparations for microscopy by action on dye. Aim of the study. Our experiment aimed і) to develop the Feulgen procedure modification that excluded the use of harsh fixation agents and mounting media and іі) to evaluate visually the effect of periodical light exposure during teaching process within 6 years onto Feulgen stained preparations quality. Materials and methods. To escape the problem of stained specimens deterioration, we omitted the use of strong fixatives and mounting media, and avoided long light expositions on microscopic preparations. For permanent microscopic preparations production, the stained specimen covered with coverslip was properly air dried and then sealed by scotch tape on coverslip perimeter instead of mounting medium use. Preparations were kept wrapped in black paper and used for teaching of medical and biological students for eproximately 20 hours each year within a 6-years period. The microphotographs of the same site in tissue made at the start and end of this period were compared in quality visually. Results and discussion. Air-drying of stained specimens between the glass slide and coverslip without mounting medium followed by their sealing with scotch tape provided preparations of good quality. Their use for teaching of students within 6 years during eproximately 20 hours per year caused no fading or other visually detectable changes in stained tissue. This was proved from comparison of microphotographs made at the start and end of this period. Conclusion. Suggested variation of the Feulgen staining method can be applied for teaching of students in medicine and biology and, possibly, for routine analyses.