Bender Klaus, Farfán María José, Schneider Peter M
Institute of Legal Medicine, Johannes Gutenberg University, Am Pulverturm 3, D-55131 Mainz, Germany.
Forensic Sci Int. 2004 Jan 28;139(2-3):135-40. doi: 10.1016/j.forsciint.2003.10.003.
DNA typing through analysis of short tandem repeats (STRs) and mitochondrial DNA (mtDNA) by means of the polymerase chain reaction (PCR) and sequencing are the common methods for the forensic identification of persons and reconstruction of kinship, especially when skeletal human remains have to be analyzed. Furthermore, samples typically found at crime scenes may be both quantitatively and qualitatively inadequate since they may contain very scarce and often degraded DNA due to exposure to heat, light, humidity, and microorganisms. In order to improve the performance of STR typing technology in those cases where DNA availability is limited, it would be desirable to have a source of degraded DNA with known properties. For this purpose, we have developed a method to prepare artificially degraded DNA under controlled conditions. By treatment of genomic DNA with sonication and DNAse I we have produced DNA fragments within a defined range of lengths. STR typing of this degraded DNA with a commercially available multiplex kit could only produce partial profiles as indicated by the absence of STR alleles with sizes >200 bp. This artificially degraded DNA can be used for the improvement and standardization of STR typing protocols when only highly degraded DNA is available for analysis.
通过聚合酶链反应（PCR）和测序分析短串联重复序列（STR）和线粒体DNA（mtDNA）进行DNA分型，是法医鉴定个人身份和重建亲属关系的常用方法，尤其是在必须分析人类骨骼遗骸时。此外，犯罪现场通常发现的样本在数量和质量上可能都不足，因为它们可能因暴露于热、光、湿度和微生物而含有非常稀少且常常降解的DNA。为了在DNA可用性有限的情况下提高STR分型技术的性能，需要有一个具有已知特性的降解DNA来源。为此，我们开发了一种在受控条件下制备人工降解DNA的方法。通过用超声处理和DNA酶I处理基因组DNA，我们产生了长度在定义范围内的DNA片段。使用市售的多重试剂盒对这种降解DNA进行STR分型，只能产生部分图谱，如大小>200 bp的STR等位基因缺失所示。当只有高度降解的DNA可用于分析时，这种人工降解的DNA可用于改进和标准化STR分型方案。
