Objectives: To compare the application effect of microwave digestion - vacuum filtration - automated scanning electron microscopy (MD-VF-Auto SEM) method and plankton gene multiplex PCR system in the diagnosis of drowning.
Methods: Lung, liver and kidney tissue of 10 non-drowning cases and 50 drowning cases were prepared for further MD-VF-Auto SEM method analysis and plankton gene multiplex PCR system analysis. The positive detection rate of the two methods in each tissue was calculated.
Results: The positive rate of the MD-VF-Auto SEM method detecting diatoms in drowning cases was 100%, and few diatoms were detected in the liver and kidney tissues of 6 non-drowning cases. By using the plankton gene multiplex PCR system, the diatom positive rate of drowning cases was 84%, and all the non-drowning cases were negative. There were significant differences in the positive rate of the liver, kidney tissues between MD-VF-Auto SEM method and plankton gene multiplex PCR system (P<0.05), as well as the total positive rate of cases. However, no significant differences were found in the positive rates of lung tissues (P>0.05).
Conclusions: MD-VF-Auto SEM method is more sensitive than plankton gene multiplex PCR system in diatom test. But the plankton gene multiplex PCR system can also detect plankton other than diatoms. Combination of the two methods can provide a more reliable basis for the diagnosis of drowning.
目的: 比较微波消解-真空抽滤-自动扫描电子显微镜（microwave digestion - vacuum filtration - automated scanning electron microscopy，MD-VF-Auto SEM）法与浮游生物基因复合扩增体系在溺死诊断中的应用效果。方法: 采用MD-VF-Auto SEM法和浮游生物基因复合扩增体系分别对10例非溺死案例和50例溺死案例的肺、肝、肾组织进行检测分析，比较两种方法在各组织中的阳性检出率。结果: 溺死案例使用MD-VF-Auto SEM法检验的硅藻阳性率为100%，在6例非溺死案例的肝、肾组织中检出少量硅藻。浮游生物基因复合扩增体系的阳性率为84%，非溺死案例的肺、肝、肾组织结果均为阴性。两种方法检测结果相比，肝、肾组织的阳性率和总阳性率差异均具有统计学意义（P<0.05），而肺组织阳性率差异无统计学意义（P>0.05）。结论: MD-VF-Auto SEM法对硅藻检验具有较高的灵敏度，而浮游生物基因复合扩增体系还可检出硅藻外的其他浮游生物。两种方法相结合，可为溺死诊断提供更可靠的依据。.
Keywords: diatom test; drowning; forensic pathology; microwave digestion-vacuum filtration-automated scanning electron microscopy method; multiplex PCR system; plankton.