Effect of Certain Dyes on the Growth In vitro of Virus Tumor Tissue from Rumex acetosa

Abstract

The effect of various dyes on the growth of virus tumor tissue from the roots of R. acetosa was tested by adding the dyes to a basal medium and culturing the tissue on these substrates for 3 weeks. Methylene blue, crystal violet, and malachite green inhibited growth at concns. above 0.01 ppm. but had no effect at lower levels. Neutral red was slightly inhibitory (about 20%) at 0.1 ppm. and higher, but higher concns. did not result in greater inhibition. Trypan blue, pyronin Y, azure A, and methyl green stimulated growth at concns. of 0.01 and/or 0.1 ppm. These 4 dyes which stimulate growth have all been used as specific stains for nucleic acids or nucleoproteins. The effect of these dyes on growth of the tumor tissue was not permanent. When the tissue was placed on the basal medium after having been grown on a medium containing a dye, the growth rate returned to normal. Unlike most other compounds, the dyes had no effect on the color of the tumor tissue, even when used at inhibitory concns., which raises the possibility of selective action of the dyes against the virus and not against the host tissue.