信件类检材脱落细胞的DNA检验

DNA Analysis of Exfoliated Cells Collected from Mail Stuffs

目的不经茚三酮显影,仅通过对可能附着有脱落细胞的部位进行DNA-STR检验,确定信纸、信封类检材上脱落细胞的最佳提取部位和转移方法。方法分别尝试直接剪取、植绒拭子擦拭、EZ-tape脱落细胞粘取器粘取等不同的转移提取方法,以商品化试剂盒(硅胶膜吸附法)直接提取,经增加PCR循环扩增、基因分析仪电泳并扫描扩增产物,最终获得DNA-STR分型。结果直接剪取法为最优转移提取方法;直接剪取信纸的折痕部位能稳定获得良好的DNA-STR分型,故应作为此类检材最佳的提取部位;粘取、直接擦拭/剪取法在信封和信纸上的字迹部位均未能获得有效的DNA-STR分型。结论纸张类脱落细胞检验的首选提取方法应为直接剪取,但剪取部位须结合案情、具体情景预判脱落细胞的最佳富集部位。折痕处应作为脱落细胞DNA检验的首选重点提取部位,可对其直接剪取而省去茚三酮显影的过程。

Objective To search the appropriate locations for the exfoliated cells to collect from mail stuffs so that their harboring DNA is capable of revealing the STR genotyping profi les without positioning through fi ngerprint development from,e.g.,ninhydrin fumigation.Methods The exfoliated cells were extracted and transferred from different positions on mail stuffs by way of respective handling of clipping,fl ocking-swab wiping or EZ-tape sticking.DNA was harvested from the exfoliated cells with the MinElute PCR Purifi cation kit,and then amplifi ed with Identifi ler Plus kit into the increased cycles of PCR.Results Clipping is the best choice to transfer the exfoliated cells on mail stuffs where the paper crease is the most suitable place for the exfoliated cells to collect and thereby have their harboring DNA unveiled of effective STR profi les,yet the wordwritten locations leaving inability to amplify the effective STR profi les.Conclusions Clipping should be the prior choice for successful extraction and transferring of DNA from the exfoliated cells on mail stuffs such that the effective STR genotyping profi les can be obtained.The crease of relevant paper is the key place to harvest eligible amount of exfoliated cells.