Taking the ‘Secret’ out of secretions: evaluation of the ParaDNA body fluid ID system at NSWHP FASS

ABSTRACT

The ParaDNA Body Fluid ID (BFID) system has been developed for use as either a screening or confirmatory test for the simultaneous identification of six biological fluids: saliva, vaginal fluid, seminal fluid, spermatozoa, peripheral blood and menstrual blood. The ParaDNA BFID kit consists of a closed, single-tube assay, incorporating multiplexed reverse transcription of mRNA and cDNA amplification, followed by fluorescent melt curve analysis with LGC’s proprietary HyBeacon DNA Probe technology. The ParaDNA instrument and early access version of the BFID kit were evaluated in this study. The evaluation included an assessment of the system’s useability, sensitivity, substrate specificity, and performance with mixtures and mock forensic samples. The ParaDNA BFID system was user-friendly, and capable of detecting most body fluids at neat concentrations. However, the system was unable to detect diluted fluids. The system’s capacity to detect saliva was also limited. Performance of the assay with different substrates was most influenced by the effectiveness of the ParaDNA sample collection tool. The tool sampled well from dried stains on fabrics, but was less effective at sampling from rayon swabs and other absorbent substrates. The system is capable of detecting fluids in mixtures, although detection appeared dependent on the combination of fluids tested.

KEYWORDS:

• ParaDNA
• body fluid identification
• rapid mRNA analysis

Acknowledgements

The authors wish to thank LGC for the opportunity to undertake the evaluation, with specific mention of Laura Dodd and Tobias Hampshire for their technical support. The authors also thank KJ Wong of PathTech for coordinating the early access testing.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

LGC provided a loan instrument for the duration of the evaluation and provided the reagents and consumables for processing 56 samples through the BFID system. In kind support was provided by NSWHP FASS.