Crystal Violet

Crystal Violet is used as an acid-base indicator. When dissolved in water, the dye has a blue-violet colour with an absorbance maximum at 590nm and an extinction coefficient of 87,000 M-1 cm-1. The colour of the dye depends on the acidity of the solution. At a pH of >1.0, the dye is green with absorption maxima at 420nm and 620nm, while in a strongly acidic solution the dye is yellow with an absorption maximum at 420nm. Spectral data: UV/Visible Absorbance: λ max (water) 584-590nm. Crystal violet is used as an active component, primary stain, of Gram stain for differentiation of Gram-negative versus Gram-positive bacteria. It has been used to check cell viability, for the staining of cells to study cell migration, invasion and cell viability and as a nontoxic DNA stain for DNA visualization in agarose gels. 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 has antibacterial, antifungal, antihelminthic, antitrypanosomal, antiangiogenic, and antitumor properties. It has shown to calcium-dependent uncouple oxidative phosphorylation. It is used to dye paper, as a component of navy blue and black inks, ball-point pens and inkjet printers. It is also used to colourize diverse products such as fertilizers, antifreezes and detergents. In forensics, gentian violet was used to develop fingerprints.