摘要
目的研究DNA降解变化与死亡时间的关系,为法医学推断死亡时间提供一种比较准确可靠的新方法。方法应用单细胞凝胶电泳(SCGE)技术结合荧光显微镜和专业的计算机图像分析技术,测定了111只小鼠在死后72h内不同时间点小鼠脑组织细胞核头半径(Head Radius,HR)、尾长度(Tail Length,TL)、头DNA(Head DNA)含量比例、尾DNA(Tail DNA)含量比例、尾矩(Tail Moment,TM)、Olive矩(Olive Moment,OM)、头面积(Head Area,HA)、尾面积(Tail Area,TA)8项参数的变化值。结果在个体死亡72h内,测定的8项参数指标中尾DNA含量比例、彗星尾长、尾矩、Olive矩、尾面积都呈增加趋势,头半径,头DNA含量比例,头面积均呈下降趋势。上述参数均与死亡时间具有高度的相关性。并将每个参数的测量值进行了多项式运算,获得了更能体现DNA降解趋势的二项式回归方程(P<0.001)和多元回归方程(P<0.001),均具有高度的统计学意义。结论应用本研究提供的72h内脑组织DNA变化与死亡时间之间呈线性关系的各组回归方程,为法医学推断死后经过时间提供了一种新的、客观的、精确的方法和参考依据。
Objective To study degradation of DNA in the cellule of rats and relationship with the postmortem interval and to find a new and accurate method to estimate the postmortem interval. Method This experiment chosed eight parameters of cell nuclear, including the tail length , the head radius, the percentage of head DNA, the percentage of tail DNA, the tail moment, the ol- ive moment, the head area and the tail area, to determine the changes of DNA degradation in brain cells of 111 rats at different inter- val between 0 and 72h postmortem by single-cell gel electrophoresis（SCGE）and fluorescent microscope connected with auto-analy- sis-image system. Results The tail length,the head radius,the percentage of head DNA, the percentage of tail DNA,the tail mo- ment, the olive moment, the head area and tail area all change greatly with the extension of postmortem interval, which indicate the degradation rate and degree of DNA in the nuclear has a close relationship with postmortem interval from 0 to 72h postmortem in rats and get regress equation and stastistic meaning（P〈0. 001）. Conclusion The equations which indicate the close relationship of degradation rate and degree of DNA in the nuclear of brain cells with postmortem interval from 0 to 72h postmortem provide an objective and exact new way to estimate the PMI.
出处
《刑事技术》
2009年第4期3-6,共4页
Forensic Science and Technology
基金
公安部应用创新计划项目
辽宁省高等学校科研项目(2008Z205)
关键词
单细胞凝胶电泳
死亡时间DNA降解
尾长度
尾矩
法医病理学
single cell gel electrophoresis
postmortem interval
DNA degradation
tail length
tail moment
forensic pathology
