Stoop Britta, Defaux Priscille Merciani, Utz Silvia, Zieger Martin
Institute of Forensic Medicine, Forensic Molecular Biology Dpt., University of Bern, Sulgenauweg 40, 3007 Bern, Switzerland.
Bern Cantonal Police, Nordring 30, 3001 Bern, Switzerland.
Leg Med (Tokyo). 2017 Nov;29:68-71. doi: 10.1016/j.legalmed.2017.10.006. Epub 2017 Oct 27.
To achieve optimal results in the forensic analysis of trace DNA, choosing the right collection technique is crucial. Three common approaches are currently well-established for DNA retrieval from items of clothing, notably cutting, swabbing and tape-lifting. The latter two are non-destructive and therefore preferable on items of value. Even though the most recently established technique of DNA retrieval by adhesive tapes is widely used since quite some years now, little information has been published so far on how well it performs compared to other methods. Even more important, when it comes to choosing the right DNA extraction method for forensic lifting-tapes, the available information one can rely on as a forensic geneticist is quite scarce. In our study we compared the two widely used, commercially available and automation suitable magnetic bead-based extraction methods "iPrep Forensic Kit" and "PrepFiler Express BTA™ Kit" to conventional organic solvent extraction. The results demonstrate that DNA extraction from standardized saliva samples applied to SceneSafe Fast™ minitapes is most efficient with phenol-chloroform. We also provide evidence that SceneSafe Fast™ minitapes perform better than wet cotton swabs in the sampling of touch DNA from cotton fabric. Applying the tape only once in every spot on the tissue is thereby sufficient for a considerably better collection performance of the tapes compared to swabbing.
为了在痕量DNA的法医分析中获得最佳结果，选择正确的采集技术至关重要。目前，从衣物上提取DNA有三种常用且成熟的方法，即裁剪、擦拭和胶带粘贴。后两种方法是非破坏性的，因此对于有价值的物品更为可取。尽管胶带粘贴这种最新确立的DNA提取技术已经广泛使用了数年，但迄今为止，关于其与其他方法相比的性能表现，发表的信息很少。更重要的是，对于为法医胶带粘贴选择正确的DNA提取方法，作为法医遗传学家可依赖的可用信息非常稀缺。在我们的研究中，我们将两种广泛使用的、适用于商业化和自动化的基于磁珠的提取方法“iPrep法医试剂盒”和“PrepFiler Express BTA™试剂盒”与传统的有机溶剂提取方法进行了比较。结果表明，应用于SceneSafe Fast™微型胶带上的标准化唾液样本，用酚-氯仿进行DNA提取效率最高。我们还提供了证据，证明在从棉织物上采集接触DNA时，SceneSafe Fast™微型胶带比湿棉签表现更好。与擦拭相比，在组织上每个部位仅使用一次胶带就能显著提高胶带的采集性能。
