Samlal-Soedhoe Radha, Willemstein Laura M, Baiker Martin, van der Weerd Jaap
Netherlands Forensic Institute, Division of Chemical and Physical Traces, P.O.Box 24044, 2490AA The Hague, The Netherlands.
Netherlands Forensic Institute, Division of Biological Traces, P.O.Box 24044, 2490AA The Hague, The Netherlands.
Sci Justice. 2017 May;57(3):174-180. doi: 10.1016/j.scijus.2017.02.001. Epub 2017 Feb 7.
We present a method in which DNA and fibre traces are jointly recovered by taping. The DNA traces are isolated by standard laboratory procedures. Fibre traces are isolated afterwards in order to improve efficiency. Two tests have been carried out to evaluate the suitability of the presented method. In the first test, possible changes in appearance of fibres due to the DNA isolation procedures are investigated. In the second test, the recovery of fibres from a contaminated surface and their possible loss due to the DNA isolation procedure are investigated. It is concluded that polyester fibres are hardly affected by the DNA isolation procedure. In contrast, a relatively large number of the investigated cotton fibres were altered. The observed differences do not indicate a structural damage to the fibre or the dyes, but rather the washing-out of some components. The observed changes may require that fibres from a known source are also exposed to the DNA isolation procedures to assess the induced changes, but do not prevent a meaningful comparison. The recovery of fibres is slightly lower than the routine procedures for fibre recovery. Therefore, it was decided to perform extra taping of the recipient in cases where fibre investigation is requested. During DNA-isolation, some of the fibres present are released from the tapes. These fibres are not lost however, as they can be found on the filter in the used DNA isolation vials.
我们提出了一种通过胶带同时回收DNA和纤维痕迹的方法。DNA痕迹通过标准实验室程序进行分离。之后分离纤维痕迹以提高效率。已经进行了两项测试来评估所提出方法的适用性。在第一项测试中，研究了DNA分离程序导致的纤维外观可能变化。在第二项测试中，研究了从受污染表面回收纤维的情况以及它们因DNA分离程序可能造成的损失。得出的结论是聚酯纤维几乎不受DNA分离程序的影响。相比之下，大量被研究的棉纤维发生了改变。观察到的差异并不表明纤维或染料存在结构损伤，而是一些成分被洗脱。观察到的变化可能需要将已知来源的纤维也进行DNA分离程序处理以评估所诱导的变化，但并不妨碍进行有意义的比较。纤维的回收率略低于纤维回收的常规程序。因此，决定在需要进行纤维调查的情况下对接收者进行额外的胶带粘贴。在DNA分离过程中，一些存在的纤维会从胶带上脱落。然而，这些纤维并未丢失，因为它们可以在所用DNA分离小瓶中的滤膜上找到。
