Crystal violet (C.I. 42555) is a CERTISTAIN dry dye that can be used to produce a Crystal violet staining solution to differentiate Gram-positive and Gram-negative bacteria in samples of human origin. ... On the other side Gram-negative bacteria are stained red or pink with the counterstain.
CRYSTAL VIOLET FOR MICROSCOPY used as a tissue stain in the preparation of light microscopy sections. In laboratory, solutions containing crystal violet and formalin are often used to simultaneously fix and stain cells grown in tissue culture to preserve them and make them easily visible, since most cells are colourless
Crystal violet binds to DNA and proteins in cells and as such can be used to detect the maintained adherence of cells