中文摘要：

为了给死亡时间推断的研究提供新的途径与数据,探讨了人死亡后组织细胞DNA含量变化与死后时间间隔关系。将离体肾、肝组织置于特定环境中,在不同时间点提取离体组织,利用激光共焦显微拉曼光谱技术和统计学方法,在拉曼位移测试范围内,对死后不同时间肾、肝组织DNA含量变化进行拉曼光谱检测与统计学分析。结果显示：人死亡后48～72h,随着死亡时间的推移,肾、肝组织Raman光谱的主要散射峰峰位没有明显变化,而其峰高有明显差异;所测组织的激光拉曼光谱特征峰的相对峰强值（I1094/I2923）随死亡时间的推移而减小。因此可以得出结论：人死亡后肾、肝组织细胞DNA含量随死亡时间延长呈下降趋势,两者之间存在线性关系。

英文摘要：

The present work is to study the relationship between DNA degradation in tissue cells and estimation of postmortem interval,and to provide a new way for the estimation of postmortem interval（PMI）.The tissue cells of kidney and liver in vitro obtained at different time points were kept in a controlled environment.The kidney tissue and liver tissue were taken out every 4 h,during 48-72 h after death at 25 ℃.The DNA content in different tissue cells was examined by means of confocal Raman micro spectroscopy with an excitation wavelength of 532 nm.Results show that the relative peak intensities （I1 094/I2 923） of confocal Raman microscopy for the tissue cells decreased gradually with the prolongation of postmortem interval from 48 to 72 h after death,while the peak intensity at 1 094 cm^-1 was reduced obviously;and the peak intensity at 1 454 and 2 923 cm^-1 did not change significantly.It is concluded that the DNA content in tissue cells decreased gradually with the prolongation of postmortem interval from 48 to 72 h after death.There is a linear relationship between the degradation rate of DNA in the tissue cells and postmortem interval.This investigation shows that Raman micro spectroscopy is useful to the estimation of postmortem interval （PMI）.