Volutin as a Substrate of the Gram Reaction

Abstract

A modified Gram procedure, with the use of an extremely diluted or acidified crystal violet solution, stained only volutin in contrast with nonstaining of the rest of cell in Gram-positive bacteria. The substrate of the Gram reaction is not only a ribonucleic acid-magnesium-protein complex in cytoplasm (Henry and Stacey 1946), but also a metaphosphate-ribonucleic acid complex in volutin and deoxyribonucleic acid in nuclei in Gram-positive cells. The isoelectric-point theory and permeability theory of the Gram stain are unsupported by the experiments.