P149 – Digital PCR: A Novel Approach to Body Fluid Identification

15:55

Wednesday August 19^th

Station 17

Duration: 12 minutes

04. Forensic biology

Michael Menear

The detection and identification of biological material is often a crucial step in advancing a forensic investigation. Determining which body fluid is associated with a crime stain has the potential to aid in the reconstruction of events while establishing a link between the donor and cells present. Molecular genetic based approaches for body fluid identification, such as mRNA profiling, offer advantages over commonly used presumptive testing methods due to the high specificity of certain mRNA markers to forensically relevant body fluids. At present, such approaches often employ quantitative PCR, massively parallel sequencing or capillary electrophoresis. However, these methodologies have major drawbacks such as the highly complex interpretation of results, therefore limiting their usefulness in real world forensic cases. Digital PCR (dPCR) is a novel technique within the forensic field which enables the absolute quantification of a nucleic acid target without the need for a standard curve. During the dPCR process, samples are partitioned across thousands of PCR micro-reactions, known as partitions, to allow for the detection of individual target molecules while also offering a higher tolerance to PCR inhibitors in comparison to current methods. This study presents two novel dPCR-based mRNA multiplexes with a high sensitivity and specificity for forensic body fluid identification. One multiplex has been designed to detect the most commonly encountered body fluids at a crime scene (blood, saliva, seminal fluid and vaginal fluid) while the second is intended to be used to identify the body fluids most relevant in sexual assault cases (sperm cells, seminal fluid, vaginal fluid and menstrual blood). Optimisation and validation data are presented here, showing that these assays have a strong potential to be integrated into forensic casework.

Keywords

Body fluid identification, mRNA profiling, Digital PCR

Authors

Michael Menear (King's College London, United Kingdom)
Dimitra Chantzi (King's College London, United Kingdom)
Federica Giangasparo (King's College London, United Kingdom)
David Ballard (King's College London, United Kingdom)
Denise Syndercombe Court (King's College London, United Kingdom)

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P149 – Digital PCR: A Novel Approach to Body Fluid Identification

Keywords

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