Investigations on the Use of Samplematrix to Stabilize Crime Scene Biological Samples for Optimized Analysis and Room Temperature Storage

• NCJ Number: 237838
• Author(s): Katherine A. Roberts; Donald J. Johnson
• Date Published: September 2011
• Length: 296 pages
• Grant Number(s): 2007-DN-BX-K172
• Agencies: NIJ-Sponsored
• Publication Type: Survey

Annotation

This research evaluates a proprietary platform technology for the dry storage of biological materials at ambient temperature.

Abstract

This coating-agent study evaluated the total amount of DNA recovered from blood, saliva, and semen samples (n=7,500) deposited on a cotton swab following a 6-24 month storage period. The study found that when considering the experimental variables for the wetting and environmental insult studies, a comparison of the various storage conditions showed that SampleMatrix-protected samples provided mean DNA yields that were equivalent or greater compared with the unprotected controls. In addition, when comparing mean recovery as a function of substrate or dilution series, significant differences in the mean recovery were observed. The data also indicated that there was no disadvantage to storing samples at room temperature compared with frozen storage; however, statistical analyses were performed in order to assess the differences in the mean DNA yield for the protected and unprotected samples. Although the results indicated that the differences were not statistically significant, a larger number of replicates are required in order to determine the significance of the treatment methods. The samples were subjected to the following experimental variables: protection with one of two SampleMatrix formulations (SM1 and SM2) as a post-collection treatment of the sample, extraction method, storage medium, dilution factor, and the method used to apply SampleMatrix as a coating agent (wet versus dry samples). The wetting agent study also evaluated the performance of the two formulations of SampleMatrix compared to water in the collection and preservation of DNA recovered from blood, saliva, and semen samples. These samples were subjected to the following experimental variables: the extraction method, the storage medium, dilution factor, and the substrate used to deposit the samples prior to recovery with cotton swabs. Two environmental-insult studies were performed. 195 figures, 71 references, and a list of publications with research findings