RNA can do better—An improved strategy for RNA-based characterization of different body fluids and skin

Abstract RNA-based identification has proven to work for cellular material from various sources of body fluids. This study addressed the questions whether simultaneous co-extraction of DNA and RNA yields similar amounts of DNA compared to established DNA extraction methods, whether RNA tests have an at least comparable sensitivity as conventional characterization tests, whether also skin epithelial cells can be characterized by specific transcripts and whether all used markers show specificity or cross-reactivity. Results showed that modification of the AllPrep DNA/RNA Mini co-extraction protocol to overnight lysis led to an at least comparable DNA amount to that obtained from QIAamp ® DNA Mini extraction. In comparison to conventional tests the RNA-markers HBB, PBGD, HTN3, STATH, PRM1, TGM4, MMP11 and GASS revealed comparable sensitivity and tissue specificity. Evaluation of suitability and specificity of three novel skin markers (CDSN, CST6 and DSC1) demonstrated cross-reaction of those markers with vaginal secretion and CDSN additionally with menstrual blood. Three established multiplexes were tested on 57 mock samples. 27 of them gave a complete result on the first try.