Laboratory of Laser Molecular Imaging and Machine Learning, Tomsk State University, Lenin Ave. 36, Tomsk, Russia, 634050.
Department of Chemistry, University at Albany, SUNY, 1400 Washington Avenue, Albany, NY, 12222, USA.
Sci Rep. 2023 Apr 3;13(1):5384. doi: 10.1038/s41598-023-31918-9.
Traces of body fluids discovered at a crime scene are a primary source of DNA evidence. Raman spectroscopy is a promising universal technique for identifying biological stains for forensic purposes. The advantages of this method include the ability to work with trace amounts, high chemical specificity, no need for sample preparation and the nondestructive nature. However, common substrate interference limits the practical application of this novel technology. To overcome this limitation, two approaches called "Reducing a spectrum complexity" (RSC) and "Multivariate curve resolution combined with the additions method" (MCRAD) were investigated for detecting bloodstains on several common substrates. In the latter approach, the experimental spectra were "titrated" numerically with a known spectrum of a targeted component. The advantages and disadvantages of both methods for practical forensics were evaluated. In addition, a hierarchical approach to reduce the possibility of false positives was suggested.
在犯罪现场发现的体液痕迹是 DNA 证据的主要来源。拉曼光谱是一种有前途的通用技术，可用于法医鉴定目的识别生物污渍。该方法的优点包括能够处理痕量物质、高化学特异性、无需样品制备以及非破坏性。然而，常见的基质干扰限制了这项新技术的实际应用。为了克服这一限制，研究了两种方法，称为“降低光谱复杂性”（RSC）和“多元曲线分辨率与加法方法”（MCRAD），用于检测几种常见基质上的血迹。在后一种方法中，实验光谱通过数值与目标成分的已知光谱“滴定”。评估了这两种方法在实际取证中的优缺点。此外，还提出了一种分层方法来降低假阳性的可能性。
