Leuco crystal Violet reacts with the heme-group in blood to give a violet color. Its application can be used to identify bloodstains that are not visible and to enhance and provide additional contrast to bloodstain patterns that are visible. This compound is ideal for developing visible and invisible blood traces, fingerprints and footprints on virtually any surface.
According to the FBI Processing guide, to make a working solution using this powder the following components are needed (not included with the powder):
Hydrogen peroxide 3%: 1000 mL
5-Sulfosalicylic acid: 20 g
Sodium acetate: 7.4 g