Effect of Fixatives' Temperatures on Subsequent Histochemical Staining

Background: Fixation is complex series of chemical events which differs for the different group of chemical substances found in tissues. Some chemical reactions, including those involved in fixation occur more rabidly at higher temperature. Objectives: Toassess the effect of varying fixatives' temperature on the quality of subsequent histochemical staining. Methods: Rabbit samples were collected including tongue tissue to demonstrate collagen fibers using Van Geison’s stain, and liver tissue to demonstrate cell morphology using Erlich’s haematoxylin. Specimens were divided into pieces; each sample was fixed in the following fixatives: formal saline, neutral buffer formalin (NBF), Carnoy’s and Bouin's fixative in different temperatures as follow 4C°, 25C°, 37C° and 60C°. There after, tissues were embedded in paraffin and cut sections into 5 micron and stained with Ehrlich’s hematoxylin and Van Gieson histochemical stains. Results: For Erlich’s heamtoxylin, formal saline gave the best result for tissues fixed at 60C°; NBF gave the best results at 37C° and 60C°. For Van Geison stain, formal saline and NBF the best results obtained at 37 C°. Conclusion: The study concluded that using 10% NBF, 10% Formal saline, Carnoy’s and Bouin’s fixatives applying different temperatures include 4C°, 25C°, 37C° and 60C° affect the subsequent histochemical staining of Ehrlich’s hematoxylin, and Van Gieson. Keywords: Fixatives, temperature, Van Geison, Erlich’sheamtoxylin, stain