Hemident is a non-destructive, presumptive field test kit for the presumptive identification of blood. Each test is a compact, disposable tube containing two chemical reagent ampoules. The suspected stain is placed inside the tube and both ampoules are broken in succession. A blue/green reaction indicates blood. A reaction will occur at up to one part per million of blood. Hemident will not distinguish between human and animal blood. To determine if blood is human specific, use a test such as Hexagon OBTI , or submit the blood for a laboratory serology analysis.