Quantitative Adsorption of Crystal Violet

The formula for crystal violet given in Conn's book (1940) implies that quantitative measure-ment of the dye adsorbed by bacterial cells should be possible by a suitable micro-Kjeldahl proce-dure. At the present time there is no satisfactory method for estimating the degree of gram posi-tivity although the need for such a procedure is recognized and is discussed by Bartholomew and Mittwer (1952). It is considered that the proce-dures reported here provide a useful tool for further quantitative studies on the gram reac-tion. The present report shows that the amount of crystal violet combined with bacteria can be