Identification of bloodstains for forensic purposes using Raman spectroscopy: method validation for donors suffered with Celiac disease

Two critical issues in forensic science are being able to identifying body fluids traces found at crime scenes, and preserving them for further analysis and as a source of DNA. However, the majority of current analytical techniques used to identify body fluids destructive. Further, current techniques, which are used at a crime scene aren’t confirmatory, meaning that they require further analysis conducted in the lab to confirm the body fluid identity. Raman Spectroscopy provides a suitable alternative to the biochemical methods being nondestructive and confirmatory. Our lab has developed a chemometric method that differentiates between the Raman spectra of five different body fluids (peripheral blood, saliva, semen, vaginal fluid, and sweat), thus identifying the sample while still preserving it. The method was developed using samples obtained from healthy donors. It is of most importance for the forensic application to evaluate the method performance in case of donors with various diseases, which might affect the biochemical composition of a body fluid. In this study we examined the ability of our method to identify dry traces of peripheral blood that cam from a donor who has Celiac Disease. To do so, peripheral blood from Celiac Disease donors were deposited on aluminum covered glass slides and dried overnight. The Raman spectra of these samples were recorded, and after preprocessing, the spectra were ran through the classification software. So far, all 20 of the Celiac spectra were positively identified as peripheral blood. This ongoing studies shows promising results that the developed method is a reliable, nondestructive, and confirmatory means of identifying body fluids