Tokutomi Tomoharu, Takada Yuzo, Kanetake Jun, Mukaida Masahiro
Department of Forensic Medicine, National Defense Medical College, Tokorozawa, Saitama 359-8513, Japan.
Leg Med (Tokyo). 2009 Apr;11 Suppl 1:S576-7. doi: 10.1016/j.legalmed.2009.02.004. Epub 2009 Mar 16.
The DNA content of different types of forensic materials can vary substantially. "Trace DNA" is the minute quantity of DNA transferred through skin contact. Here, we report three cases of identification of trace DNA using conventional short tandem repeat (STR) or mitochondrial DNA (mtDNA). DNA was successfully obtained from fabrics by swabbing or by direct extraction and subjected to STR genotyping or mtDNA typing. In two cases, there was no amplification of PCR products containing the STR loci. This indicates that the areas chosen for DNA extraction contained trace DNA and DNA from more than one source. Therefore, it is important for forensic investigators performing DNA typing to know where an item has been frequently touched by victims and/or offenders as this will influence the choice of sites on the item to be used for DNA extraction.
不同类型的法医物证的DNA含量可能有很大差异。“微量DNA”是通过皮肤接触转移的微量DNA。在此，我们报告三例使用传统短串联重复序列（STR）或线粒体DNA（mtDNA）鉴定微量DNA的案例。通过擦拭或直接提取成功从织物中获取了DNA，并进行STR基因分型或mtDNA分型。在两例案例中，含有STR位点的PCR产物未扩增。这表明用于DNA提取的区域含有微量DNA以及来自不止一个来源的DNA。因此，对于进行DNA分型的法医调查人员来说，了解物品被受害者和/或犯罪者频繁触摸的位置很重要，因为这会影响在该物品上用于DNA提取的位点选择。
