The vital staining of normal and malignant cells.-II. The staining of malignant tumours with trypan blue

Abstract In the attempt to discover a rational chemotherapeutic treatment tor cancer, the influence of various dyes on malignant growths has been investigated. There has resulted a considerable difference of opinion as to the effect of intra-vitam staining upon tumour growth. Since many acid dyes when injected into the living animal readily stain certain types of cells, the present investi­gation was carried out primarily to determine whether malignant cells stain intra-vitally with trypan blue, as do their normal prototypes. i. Previous Work.—The dyes which have been employed most in vital stain­ing are tam in blue and trypan blue. According to von Möllendorff (1921) isamin blue is precipitated at the site of injection, and produced a localised vital coloration; it slowly passes into solution again and results in time in a general staining of the animal. Trypan blue, on the other hand, is one of the most suitable of the acid dyes for effecting direct intra-vitam staining.