The Use of Polilight® in the Detection of Seminal Fluid, Saliva, and Bloodstains and Comparison with Conventional Chemical-Based Screening Tests

• Published in: Journal of forensic sciences Vol. 51; no. 2; pp. 361 - 370
• Main Authors: Vandenberg, Nicholas, van Oorschot, Roland A. H.
• Format: Journal Article
• Language: English
• Published: Malden, USA Blackwell Publishing Inc 01-03-2006; Wiley Subscription Services, Inc
• Subjects: acid phosphatase; alternate light source; Amylases - isolation & purification; Blood Stains; Body fluids; Deoxyribonucleic acid; DNA; Equipment testing; fluorescence; forensic biology; Forensic Medicine - instrumentation; Forensic Medicine - methods; forensic science; Forensic sciences; Genetic testing; Humans; Light; luminol; Male; Phadebas; Polilight; Saliva - enzymology; Scientific apparatus & instruments; Semen; Surface Properties
• ISSN: 0022-1198; 1556-4029
• DOI: 10.1111/j.1556-4029.2006.00065.x

Biological stains can be difficult to detect at crime scenes or on items recovered from crime scenes. The use of a versatile light source may assist in their detection. The ability of Polilight® to locate potential semen, saliva, and blood stains on a range of substrates and at different dilutions was tested. We also tested the use of Polilight® in comparison with conventional chemical‐based presumptive screening tests such as acid phosphatase (AP), Phadebas®, and luminol, often used in casework for detecting potential semen, saliva, and blood stains, respectively. The Polilight® was able to locate stains that were not apparent to the naked eye. The color of the material on which a stain is deposited can have an effect on the detectibility of the stain. The Polilight® was found to be comparable with the AP and Phadebas® tests in terms of its sensitivity. In a comparative study between the AP test and Polilight® on 40 casework exhibits, one false‐negative result was observed when using the Polilight®. On a series of mock casework exhibits it was determined that the Polilight® can be used successfully to locate saliva stains for DNA analysis. The sensitivity of luminol for detecting potential bloodstains was greater than that of Polilight®; however the Polilight® has particular application in instances where a bloodstain may have been concealed with paint. Overall, the Polilight® is a relatively safe, simple, noninvasive, and nondestructive technique suitable for use in forensic casework.