A Comparison of Chemical Enhancements for the Detection of Latent Blood

Luminol, Bluestar (R), and Hemascein (R) were tested to compare detection sensitivities to latent blood. Untreated, EDTA-treated human blood, and a catalytically similar blood substitute were diluted (neat to 1:1,000,000) and pipetted onto a variety of substrates. Luminol and Bluestar (R) performed similarly on all surfaces and fabrics. Hemascein (R) yielded poor results on wood surfaces, but performed well in the detection of latent blood on fabrics. Results from untreated, EDTA-treated, and synthetic blood results indicate that EDTA-treated blood is similar or slightly less sensitive than untreated blood at all dilutions and on all substrates, and the synthetic blood is less sensitive than real blood, but consistent in detection threshold and thus is useful as a training aid. Additionally, some foods and household chemicals that have previously been shown to cross-react were tested with Bluestar (R), Hemascein (R), and luminol. Hemascein (R) cross-reacted with many substances, while both luminol reagents were more discriminating.