Kaiser Christina, Bachmeier Beatrice, Conrad Claudius, Nerlich Andreas, Bratzke Hansjürgen, Eisenmenger Wolfgang, Peschel Oliver
Centre of Legal Medicine, University of Frankfurt/Main, Kennedyallee 104, 60596 Frankfurt/Main, Germany.
Forensic Sci Int. 2008 May 2;177(1):32-6. doi: 10.1016/j.forsciint.2007.10.005. Epub 2007 Dec 11.
In the past years, many publications about identification and sex-determination of dry human bones by means of DNA analysis have been published. However, few studies exist that investigate the potential use of DNA technique to determine the postmortem interval (PMI). In the present study we analyzed the rate of increasingly smaller fragments of chromosomal DNA and PMI. We examined DNA degradation in human bones with postmortem intervals ranging between 1 and more than 200 years that had been kept under comparable conditions concerning weather and soil. Following bone separation into the three different zones of interest of inner/middle/outer segments the quantity of total DNA was determined in each region. Subsequently, the degree of DNA fragmentation was estimated by searching for PCR products of defined size (150, 507 and 763 bp) with primers of the human-specific multicopy beta-actin-gene. Concerning DNA quantity we detected a significant correlation between the zone of interest and the amount of DNA. However, there was no correlation between the amount of DNA and PMI. In contrast to this, analyzing DNA using PCR showed a significant inverse correlation between fragment length and PMI. Thus, postmortem DNA degradation into increasingly smaller fragments reveals a time-dependent process. It has the potential to be used as a predictor of PMI in human bone findings, provided that environmental conditions are known.
在过去几年里，已经发表了许多关于通过DNA分析鉴定和确定干燥人类骨骼性别的出版物。然而，很少有研究探讨DNA技术在确定死后间隔时间（PMI）方面的潜在用途。在本研究中，我们分析了染色体DNA越来越小片段的降解速率与PMI之间的关系。我们研究了死后间隔时间在1年至200多年之间的人类骨骼中的DNA降解情况，这些骨骼保存在天气和土壤条件相当的环境中。将骨骼分离为内部/中间/外部段这三个不同的感兴趣区域后，测定每个区域的总DNA量。随后，通过使用人类特异性多拷贝β-肌动蛋白基因的引物寻找特定大小（150、507和763 bp）的PCR产物来估计DNA片段化程度。关于DNA量，我们检测到感兴趣区域与DNA量之间存在显著相关性。然而，DNA量与PMI之间没有相关性。与此相反，使用PCR分析DNA显示片段长度与PMI之间存在显著的负相关。因此，死后DNA降解为越来越小的片段揭示了一个时间依赖性过程。如果已知环境条件，它有可能被用作人类骨骼发现中PMI的预测指标。
