The Use of One Normal Hydrochloric Acid as a Background Cleaner for Periodic Acid–Schiff Staining Technique

Abstract

Abstract Objectives Sulfurous rinsing was considered nonessential as contained in the published periodic acid–Schiff technique because it did not clear the background better than tap water washing. The objective of this work is to elucidate the use of 1N HCl as a better background cleaner in the periodic acid–Schiff staining technique. Methods This is an experimental research. Normal samples of antrium, kidney, spleen, muscle, liver, and appendix, as well as histopathologically diagnosed samples of glycogen storage disease of the liver, alpha-1-antitrypsin deficient liver, aspergillosis nasal cavity sample, and glomerulosclerosis samples were obtained from the pathological archive. These samples were stained with a newly purchased commercially prepared Schiff reagent and overstained commercially prepared Schiff’s solution causing nonspecific background staining and laboratory-prepared Schiff reagent. Oxidation was done with 1% periodic acid for 5 minutes, washed for 5 minutes with distilled water, and stained for 10 minutes in Schiff’s reagent, but 20-minute staining was observed for the overstained Schiff reagent, oxidized in running tap water for 15 minutes. It was then rinsed in 1N HCl for 20 seconds, washed in tap water for 2 minutes, and counterstained with hematoxylin for 2 minutes. The same procedure was done for another set of slides as standards without 1N HCl rinsing done. The slides were examined under the microscope and compared for specificity. Results Slides rinsed in 1N HCl showed a clear differentiation of strong, weak, and non-PAS-positive substances. The overall effect of these staining characteristics was more pronounced in the use of laboratory-prepared Schiff. Conclusion The use of 1N HCl as a differentiator made the PAS technique more specific in its staining characteristics, especially with the use of laboratory-prepared Schiff’s reagent, which is commonly used in developing countries owing to a high cost of commercially prepared Schiff’s solution.