In sexual assault cases, it can be challenging to identify the type of body fluids/ cell types present in a crime scene sample, especially the origin of epithelial cells. Therefore, more labs are applying mRNA body fluid analysis for saliva, skin and vaginal mucosa markers. To address activity level propositions, it is necessary to assign probabilities of transfer, persistence, prevalence and recovery of DNA and mRNA markers.
View Article and Find Full Text PDFWhen DNA from a suspect is detected in a sample collected at a crime scene, there can be alternative explanations about the activity that may have led to the transfer, persistence and recovery of his/her DNA. Previous studies have shown that DNA can be indirectly transferred via intermediate surfaces and that DNA on a previously used object can persist after subsequent use of another individual. In addition, it has been shown that a person's shedder status may influence transfer, persistence, prevalence, and recovery of DNA.
View Article and Find Full Text PDFThe importance of RNA evidence is growing with new developments in RNA profiling methods and purposes. As forensic samples often can be of small quantity, extraction methods with high yields of both DNA and RNA are desirable. In order to identify the optimal DNA/RNA co-extraction workflow for forensic samples, we evaluated the performance of three frequently-used methods, two new approaches for DNA/RNA co-extraction and a manual phenol/chloroform RNA-only extraction method on blood and saliva samples.
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