Development of a Real-Time Method to Detect DNA Degradation in Forensic Samples

• NCJ Number: 240847
• Journal: Journal of Forensic Sciences Volume: 57 Issue: 2 Dated: March 2012 Pages: 466-471
• Author(s): Janice A. Nicklas, Ph.D.; Trisha Noreault-Conti, Ph.D.; Eric Buel, Ph.D.
• Date Published: March 2012
• Length: 6 pages
• Grant Number(s): 2005-DA-BX-K003
• Sponsoring Agency: National Institute of Justice (NIJ)
• Publication Format: Article
• Publication Type: Report (Technical)
• Language: English
• Country: United States of America

Annotation

This article describes the development of a Plexor technology/real-time PCR DNA degradation detection assay

Abstract

Knowledge of the degradation state of evidentiary DNA samples would allow selection of the appropriate analysis method (standard short tandem repeats [STRs] vs. mini STRs vs. mtDNA). This article describes the development of a Plexor technology/real-time PCR DNA degradation detection assay, which uses a common forward primer and two reverse primers (different fluorophores) to generate two Alu amplicons (63 and 246 bp). This very sensitive assay was optimized for reaction volume, cycle number, anneal/extend time, and temperature. Using DNA samples degraded with DNaseI, the ratio of the concentration of the short amplicon to the concentration of the long amplicon (degradation ratio) was increased versus time of degradation. Experiments were performed on a variety of environmentally degraded samples (age, sunlight, heat) and with seven commonly encountered forensic inhibitors. The degradation ratio was found to predict the observed loss of larger STR loci seen in the analysis of comprised samples. Abstract published by arrangement with John Wiley & Sons.