New Modifications of the Benzidine Stain for Study of the Vascular Pattern of the Central Nervous System

The benzidine stain demonstrates the vascular pattern by selective staining of the red blood cells contained in the vessels. Lepehne1first employed the principle of the method, namely, the benzidine test for hemoglobin, for the purpose of specifically staining hemoglobin in tissue sections; he noted that the resultant picture may resemble injection of the vessels. Later, Sjöstrand2used a benzidine stain in his studies of blood depots in the lungs and liver, and Lindgren,3in his studies on the amount of capillaries in brain tissue of young and old persons, referred to the stain as Sjöstrand's method. Pickworth,4however, was the first to adapt the principle to the specific object of demonstrating the cerebral vascular pattern, especially by use of thick frozen sections. The method consists essentially in applying the benzidine test for hemoglobin (peroxidase reaction) to frozen sections of from 200 to 300 microns in