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. This kit contains the materials needed to prepare a 500 ml working solution. To prepare, simply pour components B and C into bottle. Shake vigorously for 2-3 minutes and spray. Unmixed LCV components have a shelf life of 2 years when stored at room temperature. Once mixed, the solution is stable for 30 days.