Luminol is a reagent specifically formulated for the detection of blood at a crime scene, even if the blood is invisible to the human eye or if someone has attempted to wash the area. When luminol is sprayed on a suspected area, it will glow a white/blue when it comes in contact with blood in a darkened room (UV lamp not required). The resulting pattern can then be photographed. Our Luminol Blood Detection Reagent Spray comes in 4, 8, and 16 oz. bottles.