A Comparison of Four Presumptive Tests for the Detection of Blood on Dark Materials |
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| Authors: | Julie Butler M.S.F.S. Janet Chaseling B.S.A.S. Kirsty Wright Ph.D. |
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| Affiliation: | 1. Brisbane Scientific Section, Queensland Police Service, 200 Roma Street, Brisbane, Queensland, 4000 Australia;2. School of Environment and Sciences, Griffith University, 170 Kessels Road, Nathan, Queensland, 4111 Australia;3. Genomics Research Centre, Institute of Health and Biomedical Innovation, Queensland University of Technology, 60 Musk Avenue, Kelvin Grove, Queensland, 4059 AustraliaCorresponding author: Kirsty Wright, Ph.D. E‐mail: |
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| Abstract: | Detection of blood on dark materials is difficult for crime scene examiners so presumptive tests are used to assist. This study compared the ability of luminol, leuko crystal violet, tetramethylbenzidine, and Combur Test®E to detect whole, diluted blood (1:100) and a key‐shaped blood transfer stain (1:10), on dark cotton sheeting, tea towel, socks, synthetic carpet, and car mats. Powdered bleach was used to evaluate specificity of the blood detection tests. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall misclassification rate (OMR) assessed the quality of the blood tests. Luminol was the preferred test for diluted blood having the highest sensitivity (79%–96%), NPV (66%–93%), and the lowest OMR (3%–15%). Luminol was also found to be most efficient with a testing time on 25 items of 2 h 50 min compared with up to 8 h. Overall, luminol was the most effective method, also providing information on bloodstain patterns. |
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| Keywords: | forensic science crime scene examination blood detection luminol tetramethylbenzidine leuko crystal violet Combur Test® E |
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