目的 利用硅藻18S rRNA基因检测判定实验家兔水中尸体的死亡原因.方法 将实验家兔随机分成溺死组(n=12)、死后抛尸入水组(n=12)及空白对照组(n=6).各组按实验设计分别提取死后家兔的肺、肝、肾、脑组织和心血,匀浆后,选用硅胶密度梯度离心法分离组织中的硅藻并采用Chelex-100法提取硅藻DNA,运用PCR技术扩增硅藻特异的18S rRNA基因片段.结果 溺死组肺、肝、肾、脑组织及心血中硅藻检测多数呈阳性:肺(100%)、肝(75%)、肾(83%)、脑(66.7%)、心血(58.3%);死后抛尸入水组仅在肺组织和肾组织中各检出2例和1例阳性;空白对照组各组织全部呈阴性.结论 将PCR技术扩增硅藻18S rRNA基因片段运用到家兔水中尸体的死亡原因判断,其灵敏度和特异性均优于传统的硅藻强酸消化法.此检测方法对水中尸体的死因鉴定具有一定的应用前景.%Objective To evaluate the value of detecting the diatom 18S rRNA genes in the identification of drowning death in rabbits.Methods The experimental rabbits were randomly divided into groups drowning (n = 12), after the death of the dead bodies into the water group (n = 12) and control group (n = 6). Each group according to the experimental design were extracted after death rabbit lung, liver, kidney, brain and efort, homogenized, use silica density gradient centrifugation organization diatoms and extracted using Chelex-100 diatom DNA, PCR amplified using diatom-specific 18S rRNA gene fragment.Results For drowning group, the specific amplification products of 18S rRNA gene were detected from most kinds of tissues from drowning group : lung (100%) , liver (75%) , kidney (83%) , brain (66.7%) and heart blood (58.3%) . For postmortem submersion group, however, only two cases were detected from lung tissues and one case was detected from kidney tissues respectively. No amplified products were positive in various tissues in control group.ConclusionThe detection rate of the 18S rRNA gene with PCR-based method developed by this study was higher than the traditional method of diatom with strong acid digestion method in drowning victims. Both of the sensitivity and specificity of this method were superior to traditional methods, and it can be used as a potentialy useful tool to identify cause of death by drowning.
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