Consistent Silver Methods for Demonstrating Basement Membranes,Reticulum, and Fungi

Abstract

Modifications of the Jones method for basement membranes and reticulum, the Gomori technique for reticulum, and the methods of Grocott and Churukian for fungi are described. The stock methenamine-silver solution used in the Jones method has been reformulated by reducing the amount of silver nitrate and methenamine. Ethylene glycol has been added to help stabilize the solution. The more dilute sodium borate solution is used in this method to simplify preparation of the working methenamine-silver solution. After the kidney sections are oxidized in 0.5% periodic acid, they are treated with 0.5% thiosemicarbazide. Treatment with thiosemicarbazide accelerates the silver reaction with basement membranes. Gomori's technique for reticulum fibers has been modified to eliminate nonspecific background staining, resulting in better visualization of reticulum. Oxidation with acidified potassium permanganate instead of potassium permanganate is essential for elimination of nonspecific background staining. The Grocott procedure for fungi has been revised to shorten the staining time. This has been accomplished by the use of a hot water bath in place of a gravity convection oven. Churukian's method for fungi has been developed to eliminate the use of Gomori's methenamine-silver, which is used in the Grocott method, because it is not stable when heated. This has been accomplished by using dilute ammoniacal silver, which is more stable than methenamine-silver. Staining results achieved by these modified methods are consistent and reliable for demonstrating basement membranes, reticulum, and fungi. (The J Histotechnol 19:211, 1996)