Inhibitory Properties of Anilin Dyes

At least four phases of bacterial inhibition have been observed in the case of bacteria exposed to the action of gentian violet and related dyes: cessation of motility; inhibition of reproduction; suspension of animation; and inhibition of sporulation. Anilin dyes may show these four types of inhibition without killing the bacteria on which they are acting. There is no doubt, however, that some of the dyes, notably the acridine group and the basic triphenyl-methanes, are capable of killing some bacteria. The difficulty of distinguishing between death and inhibition of growth has led the writer to use the term “bacteriostasis” to describe the result which dyes produce. In the case of the triphenyl-methane dyes, Gram-positive bacteria are, as a rule, much more susceptible than the Gram-negative.