Comparative Analysis of Luminol Formulations

Abstract

Luminol is a valuable tool for crime scene examiners. The use of this reagent, primarily at crime scenes, allows the visualisation of occult or diluted blood, and the detection of small quantities of blood. Various different luminol formulations have been proposed over the years. In this study we have compared four different formulations with respect to luminescence and longevity. DNA profiling of blood treated with the four formulations with AMPFlSTR® SGM Plus TM and low copy number (LCN) DNA analysis allow us to make recommendations of the most appropriate luminol formulations to be used under particular case circumstances. RÉSUMÉ Le luminol est un outil de valeur pour les officiers d'identification sur les scènes de crime. L'utilisation de ce réactif permet la visualisation de sang dilué ou occulte et la détection de petites quantités de sang. Depuis des années, de nombreuses préparations différentes de luminol ont été proposées. Dans cette étude nous avons comparé quatre préparations différentes quant à leur luminescence et à leur longévité. Grâce aux analyses d'ADN du sang traité avec les quatre préparations(analyse par AMPFlSTR® SGM Plus TM et nombre de copies limité (NCL)), nous pouvons émettre des recommandations sur les préparations de luminol les plus appropriées à utiliser selon les circonstances particulières d'un cas.

On the Identification of Body Fluids and Tissues: A Crucial Link in the Investigation and Solution of Crime

“…Sometimes blood at crime scenes is difficult to see, perhaps there is a very small quantity of diluted blood (cleaning may have taken place), the blood is on a surface that makes it difficult to find (like a dark substrate or upon repainting) or there is a trail of blood-stained shoeprints leading from the scene which are no longer visible. Luminol and the more user-friendly, luminol-derived Bluestar (Bluestar Forensic, Monaco) reagent [47], are often used to detect haemoglobin and its derivatives resulting in a blue fluorescence which is captured by photography [48]. One disadvantage of such methods includes that the luminescence produced can be faint and short-lived, and in the case of luminol the visualization must be carried out in near darkness [48].…”

“…Luminol and the more user-friendly, luminol-derived Bluestar (Bluestar Forensic, Monaco) reagent [47], are often used to detect haemoglobin and its derivatives resulting in a blue fluorescence which is captured by photography [48]. One disadvantage of such methods includes that the luminescence produced can be faint and short-lived, and in the case of luminol the visualization must be carried out in near darkness [48]. Different formulations exist and those that maximise the brightness and longevity of the fluorescence and that have few adverse effects on subsequent tests for blood or on DNA profiling are preferred [48][49][50][51].…”

Hyperspectral Imaging for Bloodstain Identification

“…The luminol test is very sensitive as compared to the KM test and produces fewer false positives. Moreover, luminol test requires a dark environment [ 13 , 14 ].…”

Body fluid identification in forensics

“…The luminol test remains popular due to the relatively high sensitivity and specificity in comparison with other screening tests. However, it is limited to use in dark environments and also has disadvantages regarding the duration of illumination (about 30 seconds) and sometimes has detrimental effects on subsequent DNA analysis (15)(16)(17). Bluestar Ⓡ Forensic is another latent blood stain reagent based on chemiluminescence, and it gives more sensitive and stable results without damaging DNA and thereby allows for subsequent genotyping of stains (16,18).…”