Improved Tools for the Robust Analysis of Low Copy Number and Challenged DNA Samples

• NCJ Number: 247457
• Author(s): Pamela L. Marshall
• Date Published: May 2014
• Length: 226 pages
• Grant Number(s): 2012-IJ-CX-0016; 2009-DN-BX-K188
• Agencies: NIJ-Sponsored
• Publication Type: Research (Applied/Empirical); Report (Study/Research); Report (Grant Sponsored)
• Award: "Development of an Analytical Approach for a Robust Probability Model for LCN DNA Profile Interpretation"; Improved Tools and Interpretation Guidelines for Examining Limited Low Copy Number DNA Obtained from Degraded Single Source Samples: Bones, Teeth, and Hairs

Annotation

This research developed and improved the analytical DNA typing processes by creating a more robust system of low-copy-number (LCN) DNA that is less refractory to stochastic effects, and guidance is provided on the statistical issues needed to assess the significance of a LCN typing result.

Abstract

In order to improve LCN, several approaches were pursued. These included improvements to the robustness of the amplification through the use of APCR enhancers; increasing DNA recovery by using pressure cycling technology (PCT); improved silica columns or synchronous coefficient of drag alteration technology (SCODA); and more efficient reduction of inhibition. Each of these approaches was found to contribute to improving the efficacy of analysis by either increasing the yield of the sample, more effective purification of a sample, or increasing amplification efficiency (e.g., decreased stutter). The result of such processing is that some DNA samples that traditionally yield too little DNA for typing may become suitable for routine analysis, or a more effective methodology may be developed that will enable analysis of samples that typically have not been typeable. In addition, more challenged samples may be analyzed by combinations of better purification columns, PCT, SCODA, and PCR improvement. 14 tables, 31 figures, and 202 references