mRNA profiling of mock casework samples: Results of a FoRNAP collaborative exercise

In recent years, forensic mRNA profiling has increasingly been used to identify the origin of human body fluids. By now, several laboratories have implemented and also use it in criminal casework. 2018 FoRNAP (Forensic RNA Profiling) group was established among a number these with aim sharing experiences, discussing optimization potential, identifying challenges suggesting solutions regards To compare methods results collaborative exercise organized within group. Seven from four countries received 16 stains, comprising six pure fluid / tissue stains ten mock casework samples. The were asked analyze provided their in-house method (PCR/CE or MPS) markers choice. Five DNA/RNA co-extraction strategy. Overall, up 11 per analyzed. We found that using different extraction analysis as well multiplexes can be applied casework-like general, high input samples typed accuracy by all laboratories, regardless used. Irrespective strategy, low mixed more challenging interpret since, alike DNA profiling, higher dropped out and/or additional unexpected not consistent cell type question detected. It could shown plethora but valid interpretation strategies exist are successfully Forensic Genetics community. Nevertheless, efforts aiming at optimizing harmonizing approaches order achieve consistency between might desirable future. simultaneous alongside showed an effective approach only present donor(s) stain. This allows investigators gain valuable information about crime scene course events case.