AbstractOne of the most popular and reliable histochemical techniques to demonstrate carbohydrates and mucosubstances in tissues is the periodic acid-Schiff (PAS) technique. In the course of this technique, the aldehyde group produced in the section by periodic acid oxidation reacts with the Schiff reagent to form a magenta colored final product. All such substances that take up magenta color are known as PAS-positive substances. The new histochemical technique described in this paper demonstrates all PAS-positive substances without using the Schiff reagent. The technique uses a nondecolorized dilute solution of basic fuchsin in combination with a dilute solution of periodic acid to form a crimson final reaction product with all types of PAS-positive substances. The new technique, which is economical and simple to carry out, requires a shorter time and can be performed on formalin fixed, paraffin processed tissues. (The J Histotechnol14:155, 1991)