小鼠骨骼肌细胞核DNA降解与死亡时间的关系

目的　监测小鼠死后骨骼肌核内DNA降解的情况 ,探讨死后细胞核DNA降解的一般规律。方法　建立小鼠死亡模型 ,在死后 72h内 ,以 12h的间隔取骨骼肌样本进行单细胞凝胶电泳 ,在荧光显微镜下测量彗星图像 ,并作统计学分析。结果　机体死后 ,骨骼肌细胞在电泳图像上出现了明显的彗星形拖尾 ,L/W比值随死亡时间而逐渐增大 ,二者呈一定的线性关系。结论　单细胞凝胶电泳技术可以应用于早期死亡时间推断。

A study of the relationship between the postmortem interval and nuclear DNA degradation of muscle cells in mice

Objective To evaluate the regular degradation of nuclear DNA of muscle cells in mice after death. Method A mouse death model was established. Skeletal muscle was sampled at 12-hour-interval within 72 hours after death. After single-cell gel electrophoresis, the comet-length and comet-width were scaled under fluorescent microscope. Results An evident comet tailing was observed in DNA of muscle cells after electrophoresis. The ratio of L/W increased with the extension of postmortem interval, which was correlated linearly with PMI from 0 to 48h postmortem. Conclusion DNA degradation by single-cell gel electrophoresis may be used as a predictor of PMI.