Templeton Jennifer E L, Taylor Duncan, Handt Oliva, Linacre Adrian
School of Biological Sciences, Flinders University, Bedford Park, Adelaide, South Australia, 5042, Australia.
School of Biological Sciences, Flinders University, Bedford Park, Adelaide, South Australia, 5042, Australia; Forensic Science South Australia, Adelaide, South Australia, 5000, Australia.
Forensic Sci Int Genet. 2017 Jul;29:276-282. doi: 10.1016/j.fsigen.2017.05.006. Epub 2017 May 21.
Fingermarks are a source of human identification both through the ridge patterns and DNA profiling. Typing nuclear STR DNA markers from previously enhanced fingermarks provides an alternative method of utilising the limited fingermark deposit that can be left behind during a criminal act. Dusting with fingerprint powders is a standard method used in classical fingermark enhancement and can affect DNA data. The ability to generate informative DNA profiles from powdered fingerprints using direct PCR swabs was investigated. Direct PCR was used as the opportunity to generate usable DNA profiles after performing any of the standard DNA extraction processes is minimal. Omitting the extraction step will, for many samples, be the key to success if there is limited sample DNA. DNA profiles were generated by direct PCR from 160 fingermarks after treatment with one of the following dactyloscopic fingerprint powders: white hadonite; silver aluminium; HiFi Volcano silk black; or black magnetic fingerprint powder. This was achieved by a combination of an optimised double-swabbing technique and swab media, omission of the extraction step to minimise loss of critical low-template DNA, and additional AmpliTaq Gold DNA polymerase to boost the PCR. Ninety eight out of 160 samples (61%) were considered 'up-loadable' to the Australian National Criminal Investigation DNA Database (NCIDD). The method described required a minimum of working steps, equipment and reagents, and was completed within 4h. Direct PCR allows the generation of DNA profiles from enhanced prints without the need to increase PCR cycle numbers beyond manufacturer's recommendations. Particular emphasis was placed on preventing contamination by applying strict protocols and avoiding the use of previously used fingerprint brushes. Based on this extensive survey, the data provided indicate minimal effects of any of these four powders on the chance of obtaining DNA profiles from enhanced fingermarks.
指纹既是通过纹路模式也是通过DNA分析进行身份识别的一种来源。从先前增强处理过的指纹中分型核STR DNA标记提供了一种利用犯罪行为中可能留下的有限指纹沉积物的替代方法。用指纹粉擦拭是经典指纹增强中使用的标准方法，并且会影响DNA数据。研究了使用直接PCR拭子从粉末状指纹中生成信息丰富的DNA图谱的能力。在执行任何标准DNA提取过程后生成可用DNA图谱的机会微乎其微时，直接PCR被用作一种手段。如果样本DNA有限，对于许多样本而言，省略提取步骤将是成功的关键。在用以下一种指纹粉末处理后，通过直接PCR从160个指纹中生成了DNA图谱：白色哈多奈特；银色铝粉；HiFi火山丝黑色；或黑色磁性指纹粉。这是通过优化的双拭子技术和拭子介质的组合、省略提取步骤以尽量减少关键低模板DNA的损失以及添加AmpliTaq Gold DNA聚合酶来增强PCR实现的。160个样本中有98个（61%）被认为可“上传”至澳大利亚国家刑事调查DNA数据库（NCIDD）。所描述的方法所需的工作步骤、设备和试剂最少，并且在4小时内完成。直接PCR允许从增强的指纹中生成DNA图谱，而无需将PCR循环数增加到超出制造商的建议。通过应用严格的方案并避免使用先前用过的指纹刷，特别强调了防止污染。基于这项广泛的调查，所提供的数据表明这四种粉末中的任何一种对从增强指纹中获得DNA图谱的可能性影响极小。
