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Use of Pressure Cycling Technology To Enhance DNA Yield and Profile Success in Touch Samples

NCJ Number
Date Published
July 2014
26 pages
The findings and methodology are presented for a study that assessed whether pressure cycling technology (PCT) can improve DNA recovery from low-yield samples of touch DNA.

PCT is done in a Barocycler instrument that uses alternating periods of high hydrostatic and ambient pressure during DNA extraction. This project assessed the integration of a PCT step into an existing DNA extraction process by attempting to determine the optimal time and temperature of pressure cycling and by performing an internal validation with tests of sensitivity, reproducibility, mock casework samples, and effects of inhibitors. In all studies, the PCT-treated samples were compared to equivalent untreated samples. Low amounts of DNA were used to mimic touch DNA samples. Overall, the assessment found limited indications that PCT improved results from mock touch casework samples. Thus, the assessment did not demonstrate significant yield improvements. This report recommends that many more samples be used to assess the significance of PCT. Such research should test the effect of pressure on the inhibitor and DNA or adding aliquots of pressure-treated inhibitor directly to the Quantifiler Duo master mix in the absence of DNA. 10 tables, 3 figures, and 18 references

Date Published: July 1, 2014