Combining microRNA analysis with DNA profiling in a single stream process

Thousands of microRNAs are present in biological material and are rich in information due to their
differential expression and regulatory function. MicroRNAs have a potential to be ideal forensic
markers due to their small size (~22nt), high abundance per cell, and sensitive and specific
PCR-based detection. These advantageous properties increase the chances of successful analysis from challenging crime scene samples. In addition, we have demonstrated previously that informative microRNA expression levels can be obtained from common DNA extracts.
Following our pilot project on a single stream process with the integration of microRNA analysis
into a DNA profiling multiplex, we now present our progress on this topic with our work on the
identification of endogenous controls and a larger set of microRNAs that can be used for body fluid identification of blood, saliva, skin cells, vaginal material, and semen. This work will result in a panel of microRNAs that, following multiplexing, allow body fluid identification within a single test.
It has been demonstrated that specific microRNA expression levels can be characterised using a
genetic analyser. After multiplex stem-loop reverse transcription and PCR with labelled primers, it was shown that blood and saliva can successfully be distinguished by amplifying hsa-miR-451 and hsa-miR-205. This will now be expanded with our newly identified markers to allow a full body fluid identification test on single source and mixed samples.