This study examines the use of tissue-specific DNA methylation as a method for the epigenetic discrimination of forensic samples.
The results of this study allow the identification of three new loci able to distinguish blood and two new loci able to distinguish saliva and vaginal epithelia, respectively. In this study, researchers validated and identified loci able to discriminate blood, saliva, semen, and vaginal epithelia. The researchers established the minimum amount of DNA able to provide reliable results using methodologies such as pyrosequencing and high-resolution melt (HRM) analysis for the different markers identified. The researchers also performed an alternative bioinformatic analysis of data collected using an array that studied methylation in over 450,000 individual cytosines on the human genome. Researchers were able to sort the locations that showed potentially higher methylation differences between body fluids and investigated over 100 of them using HRM analysis. The use of DNA methylation patterns to aid forensic investigations started with a publication in 2010, therefore each small contribution such as this work may, similarly to what occurred in the biochemistry field, result in the discovery of a method able to put the technology in the hands of forensic analysts.