A Study on the Stainability and DNA Conservation of Tissue Slides according to Fixation Time and Temperature

In this paper, the factors affecting tissues during fixation on slides were determined by changing the tissue type, fixation time, and temperature. Also, stainability and DNA conservation were evaluated. The tissues selected were parenchymal and intestinal tissue. The stainability was evaluated using hematoxylin and eosin staining and a special stain suitable for the tissue. DNA conservation was evaluated using the DNA integrity number (DIN) for stability evaluation after purity measurement. The results showed that, at all temperatures, as time increased, there was no histomorphological difference and the stainability tended to intensify. The intestinal tissue tended to have less mucosal change and proper muscle layer degeneration. There was little difference in the purity. However, the longer the fixation time, the lower the DIN value for DNA. Significant differences were identified at 25°C and 50°C. This means that fixation at 4°C is the more safe for DNA. This experiment confirmed that, between the time and temperature conditions associated with fixation, time had a greater effect on both staining and DNA conservation. The results of this study are expected to provide basic data for future research on the setting appropriate conditions for fixation for histopathological examinations or diagnoses.