Since assays for determining human origin for blood are currently time-consuming and destructive to the sample, this article reports on research that demonstrates Raman spectroscopy can be effectively applied as a non-destructive technique for differentiating human blood from a wide survey of animal blood.
The characterization of suspected blood stains is an important aspect of forensic science. Determining the origin of a blood stain is a critical, yet overlooked, step in establishing its relevance to the crime. In the reported study, a Partial Least Squares-Discriminant Analysis (PLS-DA) model was built from a training set of the near infrared Raman spectra from 11 species. Various performance measures, including a blind test and external validation, confirmed the discriminatory performance of the chemometric model. The model demonstrated 100-percent accuracy in its differentiation between human and nonhuman blood. These findings further demonstrate a great potential of Raman spectroscopy to the field of serology, especially for species identification of a suspected blood stain. (publisher abstract modified)