Detection of plankton by molecular biological method.

溺水死亡的诊断通常基于对身体的外部检查和尸检结果以及实验室调查。用化学消化法检测器官中的浮游生物通常是在身体上进行的，以诊断溺水。在本研究中，我们试图通过对蓝藻(约1um大小)中聚球藻属的微浮游动物的16S核糖体DNA(RDNA)进行PCR分析，尝试将分子生物学方法用于溺水诊断。我们设计了与已测序的微浮游动物16S rDNA可变区互补的引物。比较了三种微浮游植物、其他五种蓝藻、硅藻、Staurasturum(绿藻)、Bikal湖细菌和人类的PCR产物。用所设计的引物对微浮游动物模板DNA进行了特异性扩增，得到了DNA的pigg顺序。当微微浮游生物模板与人肺组织混合时，至少需要10 ng模板DNA才能获得PCR产物。从肺组织中分离微浮游动物使聚合酶链式反应的灵敏度提高了一百多倍。从福尔马林固定的溺水组织中获得微浮游动物的特异性PCR产物。利用浮游微藻16S rDNA成功地进行了溺水的分子生物学诊断。

A diagnosis of death by drowning is normally based on findings from the external examination of the body and autopsy together with laboratory investigations. The detection of planktons in organs using the chemical digestion method is routinely performed on cadavers for the diagnosis of drowning. In the present study, we attempted to use the molecular biological method for the diagnosis of drowning by PCR analysis of the 16S ribosomal DNA (rDNA) of picoplanktons, belonging to the Synechococcus genus in cyanobacteria (approximately 1 mum in size).We designed primers complementary to the variable regions of 16S rDNA of the picoplankton we had sequenced.A comparison was made of the PCR products from the three picoplanktons, five other cyanobacteria, Melosira (diatom), Staurasturum (green alga), bacteria from Lake Bikal, and humans. The picogram order of template DNA from picoplankton was specifically amplified by the primers. When the template of picoplankton was mixed with human lung tissue, at least 10 ng of template DNA was needed to obtain a PCR product. The isolation of the picoplankton from lung tissue increased sensitivity of PCR more than a hundred-fold. The specific PCR products of the picoplankton were obtained from formalin-fixed drowning tissue. Molecular biological diagnosis of drowning was successful using picoplankton 16S rDNA.