Simplified Manufacture and Histochemical Use of the Schiff Reagent

Abstract

Schiff reagents were made by two methods. The first procedure gave a Schiff reagent of pH 1.8-2.4. It was accomplished by passing sulfur dioxide into 0.5% aqueous fuchsin solution at room temperature, stopping at reddish violet, and decolorizing allowed to occur on standing. In another method, 1.5 ml of 5.6% sulfurous acid was added to 100 ml 0.5% fuchsin solution and the mixture produced in several hours a colorless Schiff reagent of pH 3. The solution remained unchanged for some weeks when kept stoppered in a refrigerator. To test these Schiff reagents, histochemical examinations were carried out with Feulgen and McManus reaction in various pH ranges. These experiments showed that the Feulgen reaction was optimum at pH 3, the McManus reaction at pH 2.4.