THE development of a simple quantitative Gram staining technique has been attempted by numerous observers1,2, not only for its possible practical uses but also because of its potential value in studies on the mechanism of the staining reaction on intact cells and on extracellular material3, as well as the relationship between degree of Gram-positivity and physiological state of the organisms. The recent procedure of Barbaro and Kennedy4 is reasonably accurate but, since it involves measurement of dye nitrogen taken up by a suspension of organisms, it is rather laborious for practical application.