Comparative Examination of Commonly Used Some Fixatives with Routine Histochemical Staining’s for The Optimal Histological Appearance in The Gill Tissue of Zebrafish

Histopathological studies related to Zebrafish which are used as a model organism in researching the pathogenesis of many diseases increase day by day. Because of the increasing importance of zebrafish research, experiments on this animal model are more prominent and gill tissue is frequently examined in various disease models using zebrafish. As it is known, at the end of the experimental animal model studies, if the histopathological examination is to be done, the tissues should be fixed. The purpose of fixation is to keep cellular and extracellular components in vivo as much as possible. Therefore, the choice of fixation methods and fixatives has a significant effect on tissue processing. In this study, we aimed to optimize fixation techniques and staining protocols for producing ideal slides and histological images of gill tissue in zebrafish. In our study, to determine the optimal histology in the zebrafish-gill tissue, the tissues were fixed with Bouin’s, Carnoy’s, 10% neutral buffered formalin (NBF), Davidson’s, and Dietrich’s solutions. Following the routine tissue processing, the sections were stained with Hematoxylin and Eosin (H&E) and Masson’s Trichrome (MT) stains. Consequently, tissue morphology was best preserved with Bouin’s and NBF solutions. The best results in H&E stain were obtained from tissues fixed with NBF solution, while Dietrich's solution fixation was found to be ideal for MT staining