Application of Raman hyperspectral imaging for bio-fluid spots segmentation and characterization on cotton supports

Forensic analysis of biological traces based on advanced approaches like DNA fingerprinting, serology and toxicology plays a crucial role in suspect identification and event reconstruction. In the last decades, non-destructive spectroscopic and imaging techniques have often permitted to gather preliminary information on the presence of biological fluids in specific locations of a crime scene. This study combines Raman hyperspectral imaging with chemometrics to characterize biological stains on cotton supports. Our results (obtained through the application of Soft Independent Modelling of Class Analogy - SIMCA - Principal Component Analysis - PCA - and Partial Least Squares Discriminant Analysis - PLS-DA) show that such a combination allows stains of 4 distinct biological fluids (i.e., blood, urine, sperm and saliva) to be successfully differentiated, paving the way to the development of a robust and accurate tool for on-site recognition and identification of liquid traces of forensic interest.