This study provides a comparative assessment of emerging technologies for body fluid identification.
The goal of this study is to perform a comparative assessment of these emerging “omic” based technologies for body fluid identification (epigenome, transcriptome, proteome). The comparative assessment of the strategies discussed in this study provides valuable information to the forensic community that can aid in the development of new research and facilitate technology transfer. The work entails a thorough evaluation of error rates, sensitivity, and specificity of several approaches—namely epigenetics, mRNA profiling, and proteomics—as compared to conventional workflows using immunochromatographic assays. Biological fluid detection and identification provides important contextual information in a forensic investigation. While genetic testing can help establish whom DNA may have come from, only serological testing can provide an indication of the body fluid or tissue from which a DNA profile may have originated. Given the limitations, current serological techniques lack sufficient sensitivity and specificity. As a result, several novel approaches to identifying biological fluids have been explored in recent years. These include the use of epigenetic modifications (DNA methylation), messenger ribonucleic acid (mRNA) markers, and proteomic identification of protein biomarkers. Forensic practitioners have repeatedly stressed that the identification of biological stains can be a significant challenge for case-working serologists. They often find it difficult to detect and identify low levels of biological stains, particularly those containing vaginal/menstrual fluids. However, such low-level samples routinely produce STR profiles. Furthermore, for certain types of biological fluids, the lack of confirmatory test methods can prevent a positive determination of the serological origin of the DNA profile. The data from this study represents a snapshot in time for the development of these “omic” methods. Extensive research and validation remain for these procedures; however, the technology has been widely heralded and applied in medical diagnostics and its implementation in forensics is long overdue.