NCJ Number
242688
Journal
Canadian Society of Forensic Science Journal Volume: 45 Issue: 4 Dated: December 2012 Pages: 179-194
Date Published
December 2012
Length
16 pages
Annotation
This study assessed the possibility of using RNA transcript detection by duplex realtime PCR (RT-qPCR) to determine the age of body fluid stains commonly encountered in forensic biology.
Abstract
Time of deposition of a biological stain can be of value to determine the relevance of a sample in a forensic investigation. This study assessed the possibility of using RNA transcript detection by duplex real-time PCR (RT-qPCR) to determine the age of body fluid stains commonly encountered in forensic biology. Targets included the ribosomal 18S RNA and the human -actin, GAPDH and cyclophilin A mRNAs. The results obtained from samples stored over a 6 month interval showed that the rate of RNA decay is similar for all markers tested in each type of tissue. For blood and semen, RNA degradation profiles of each target are correlated with time of storage. Moreover, the degradation rate of each target differs depending on the nature of the stain. In this study, decay rates of rRNA vs. mRNA targets did not exhibit significant differences, the authors suggest, however, that the degradation profiles of individual RNA markers may be useful to estimate the age of a sample as an exclusionary test. To the authors' knowledge, this is the first study to investigate RNA stability in dried blood, semen, and saliva stains concurrently for age determination. The authors also assessed the impact of freezing biological stains at -80 degrees C to determine if subsequent analysis would result in the loss of relevant information. (Published Abstract)