Effect of Fixatives Temperatures on Subsequent Histochemical Staining

Abstract

This study was conduct in Sudan University of Science and Technology . During the period from January 2011 to December 2012. To assess the effect of tissue fixation temperatures on subsequent histochemical staining. Rabbit samples were collected to examine the influence of varying fixatives temperatures on the quality of staining of some rabbit organs include lung to demonstrate reticular fiber using Gordon and Sweets, tongue to demonstrate collagen fibers using Van Geison’s stain, aorta to demonstrate elastic fibers using Verhoff’s stain, large intestine to demonstrate mucin using Alcian blue and liver to demonstrate cell morphology using Erlich’s and Weigert’s hematoxylin and glycogen using PAS. Specimens were divided into pieces, each sample was fixed in following fixatives: formal saline, neutral the buff°er formaldlyde, Carnoy’s and Bouin's fixative at different temperatures 4 C , 25° C, 37 °C and 60°C. thereafter, tissues were paraffin – embedded and 5 micron sections were cut using rotary microtome and stained with different histochemical staining includes Ehrlich’s hematoxylin, Weigert's hematoxylin, Feulgen, Van Gieson, Gordon and Sweet’s, Verhoeff's, Periodic Acid Schiff and Alcian Blue. For Erlich’s heamtoxylin, formal saline gave the best result for tissues fixed at 60°C, NBF gave the best results at 37° C and 60°C. For Weigert's hematoxylin, formal saline gave better results at 37°C, NBF gave better results at 37° C and 4°C. For feulgen stain the best results were obtained at 37°C when fixed in formal saline. And when fixed in neutral buffer formaldehyde, better results were obtained at 37°C. For Van Geison stain , formal saline and NBF the best results obtained at 37° C For Gordon and sweet, Formal saline fixative gave better results at 37°C but NBF gave better result's at 25°C and 4C. For Verhoff’s stain, Formal saline fixative gave the best results at 4°C , 37°C and 60°C. NBF gave the best results at 37°C whereas Bouin's and Carnoy's fixative gave the best results at all temperatures. PAS formal saline fixative gave the best results at 4° C but NBF fixative gave better results at 37° C. In alcain blue stain formal saline fixative gave better results at 37°C and 60°C, but the best results were obtained at 37°Cwhen fixed by NBF.