Office of the Chief Forensic Scientist, Victoria Police Forensic Services Centre, 31 Forensic Drive, Macleod, Victoria 3085, Australia; Department of Genetics, La Trobe Institute for Molecular Sciences, La Trobe University, Melbourne, Victoria 3086, Australia.
Forensic Sci Int Genet. 2014 Jan;8(1):179-86. doi: 10.1016/j.fsigen.2013.09.005. Epub 2013 Sep 19.
The use of tapelifting for collection of touch DNA from fabrics is routine in many jurisdictions. However, there is a paucity of data relating to the effectiveness of different types of tapes for tapelifting, the amount of tapelifting required to generate a useful profile, and whether or not tapelifting is more effective than swabbing from various substrates. This research investigates these questions by comparing two tapes of different adhesive strength currently used in forensic casework (Scotch Magic tape and Scenesafe FAST minitapes), for sampling from touch deposits on four different fabrics-cotton flannelette, cotton drill woven fabric, polyester/cotton plain woven fabric and polyester strapping. Touch DNA was deposited on four replicates of each substrate. Separate areas of each substrate replicate were sampled, either by taping with one of the two tapes or by wet/dry swabbing with cotton swabs. Tape was applied over the defined sampling area once or repeatedly for various numbers of applications. DNA was extracted, quantified and profiled from all tape and swab samples as well as the corresponding sampled substrates. Significantly more DNA was extracted, and a higher proportion of alleles detected, from Scenesafe FAST tape than from Scotch Magic tape. The amount of DNA and number of donor alleles detected generally increased as the tape was reapplied to the surface, although a threshold of collection was seen for both types of tape. For two out of four substrates, taping with Scenesafe FAST collected more DNA than swabbing and, for three substrates, generated a greater median number of donor alleles. There was no significant difference in numbers of alleles between swabbing and taping from flannelette. Based on these findings, it is recommended that a tape with stronger adhesion (such as Scenesafe FAST tapelifters) is generally preferable; that more than one application of tape is suggested (however, increasing the amount of times the area is sampled can diminish collection efficiency); and that there is an advantage using tapelifting rather than swabbing for fabrics unless, such as with flannelette, there are many loose fibres easily removed during the sampling process.
从织物上采集接触性 DNA 时，使用胶带提拉法在许多司法管辖区已成为常规操作。然而，关于不同类型的胶带在提拉法中的有效性、生成有用图谱所需的提拉次数，以及提拉法是否比从各种基质上擦拭更为有效，相关数据却很少。本研究通过比较两种目前在法医工作中使用的不同粘性胶带（Scotch Magic 胶带和 Scenesafe FAST 迷你胶带），从四种不同织物（棉绒布、棉斜纹布、涤棉平纹布和聚酯捆扎带）上的接触性斑迹中采集样本，对这些问题进行了研究。在每个基质的四个重复样本上，都有接触性 DNA 沉积。每个基质样本的不同区域分别采用两种胶带之一进行胶带取样，或者用棉签进行湿/干法擦拭取样。对各种应用次数的胶带进行一次或重复多次取样。对所有胶带和擦拭样本以及相应的取样基质进行 DNA 提取、定量和图谱分析。从 Scenesafe FAST 胶带中提取的 DNA 量更多，可检测到的等位基因比例也更高，与 Scotch Magic 胶带相比，这一结果具有显著差异。随着胶带重新应用于表面，DNA 量和供体等位基因的数量通常会增加，尽管两种胶带都存在收集阈值。对于四种基质中的两种，用 Scenesafe FAST 胶带进行胶带取样比擦拭取样收集到的 DNA 更多，对于三种基质，产生的供体等位基因中位数更多。在 Flannelette 基质上，擦拭取样和胶带取样的等位基因数量没有显著差异。基于这些发现，建议一般优先使用粘性更强的胶带（如 Scenesafe FAST 胶带提拉器）；建议对胶带进行多次取样（然而，增加取样区域的次数可能会降低采集效率）；除非有很多易于在取样过程中脱落的松散纤维（例如在绒布上），否则使用胶带提拉法比擦拭法更有优势。
