NCJ Number
203502
Journal
Journal of Forensic Sciences Volume: 48 Issue: 6 Dated: November 2003 Pages: 1280-1287
Date Published
November 2003
Length
8 pages
Annotation
This article discusses the use of SYBR Green assay to access genotype and DNA quantity information in forensics by analysis of a sex determination marker.
Abstract
Routine forensic DNA analysis, based on short tandem repeat (STR) markers, can be performed successfully on most evidence materials found at a crime scene. But biological material are often degraded and contain scarce amounts of DNA, limiting the possibility to perform an analysis based on nuclear markers amplified in large fragments. In order to determine whether an evidence material contains sufficient amounts of DNA, a sensitive quantification assay is required. The use of the SYBR Green assay was evaluated to access genotype and DNA quantity information by analysis of a sex determination marker. Human male and female blood samples, serving as sex determination controls, were extracted using the Wizard Genomic DNA Extraction Kit. The sex determination assay is based on melting curve analysis demonstrating a 3-bp deletion on the X chromosome within the analyzed fragment. The melting curve for a DNA sample from a male shows a clear difference to that from a female. A total of 23 control samples of known gender were analyzed, resulting in correct male or female specific melting curves for all samples. The results show that the SYBR Green assay will be useful for PCR optimization, quantification, and DNA typing in forensic analysis of certain samples and may provide a cost-effective alternative to the TaqMan quantification assay. The sex determination marker used to evaluate the SYBR Green assay will be useful in analysis of old and degraded DNA, or samples with minute amounts, where the routine analysis often fails, and has been successfully applied to a number of forensic samples containing limited amounts of DNA. Further evaluation and validation of the technology is necessary for use in routine forensic analysis. 4 tables, 5 figures, 23 references