Tags: Chemical Compound, Chemical Substance.
Trypan blue is a vital stain used to selectively colour dead tissues or cells blue. It is a diazo dye.Live cells or tissues with intact cell membranes are not coloured. Since cells are very selective in the compounds that pass through the membrane in a viable cell trypan blue is not absorbed; however it traverses the membrane in a dead cell. Hence dead cells are shown as a distinctive blue colour under a microscope.
