NCJ Number
246753
Journal
Forensic Science International: Genetics Volume: 8 Issue: 1 Dated: January 2014 Pages: 170-178
Date Published
January 2014
Length
9 pages
Annotation
Preserving DNA is important for validation of prospective and retrospective analyses, requiring many expensive types of equipment e.g., freezers and back-up generators and energy.
Abstract
Preserving DNA is important for validation of prospective and retrospective analyses, requiring many expensive types of equipment e.g., freezers and back-up generators and energy. While freezing is the most common method for storing extracted DNA evidence or well-characterized DNA samples for validation studies, DNAstable Biomatrica, a commercially available medium for room temperature storage of DNA extracts was evaluated in this study. Two groups of samples consisting of different DNA quantities were investigated, one ranging from 20 to 400ng group 1 and the other one ranging from 1.4 to 20ng group 2. The DNA samples with and without DNAstable were stored at four different temperatures ~25 degrees C room temperature, -20 degrees C, 37 degrees C or 50 degrees C. DNA degradation over several months was monitored by SYBR Green-based qPCR assays and by PCR amplification of the core CODIS STR markers for group 1 and 2 DNA samples, respectively. For the time points tested in this study up to 365 days, the findings indicate that the -20 degrees C controls and the DNAstable protected samples at room temperature provided similar DNA recoveries that were higher compared to the unprotected controls kept at RT, 37 degrees C or 50 degrees C. These results suggest that DNAstable can protect DNA samples with effectiveness similar to that of the traditional -20 degrees C freezing method. In addition, extrapolations from accelerated aging experiments conducted at high temperatures support that DNAstable is an effective technology for preserving purified DNA at room temperature with a larger protective impact on DNA samples of low quantity <20ng.