A novel method for blood detection using fluorescent dye

Abstract

Detection of the body fluid present at a crime scene is essential for any forensic investigation. Amongst all the body fluids (sweat, semen, vaginal fluid, saliva, etc.,) blood is the most frequently encountered evidence at the crime scene. Currently, reagents like benzidine, ortho-toluidine, tetramethylbenzidine, phenolphthalein, leucomalachite green, luminol, and fluorescein are used to screen the presence of blood on different surfaces (porous/nonporous). Most of these tests are based on colorimetric changes owing to the nature of hemoglobin to catalyze the oxidation of chromogenic compounds. Apart from aiding the investigation, these reagents show toxic behavior (DNA damage, carcinogenic, etc.) and false-positive results. Hence, to circumvent this issue, the present study attempts to develop a state-of-art methodology for preliminary blood detection and screening using fluorescein-derived 2′,7′-dichlorofluorescein di-acetate (DCFDA) dye. It is hereby proposed that the fluorescein-based dye can successfully detect blood and bloodstains aged up to 20 days. Moreover, supplemental experiments have suggested that the dye doesn't interfere with DNA integrity- causing any damage to DNA. Parallelly, no false-positive reactions have been observed as tested against similar-looking substances.