中文摘要：

背景与目的：研究紫外线（Ultraviolet，UV）诱导K562细胞DNA损伤情况，评价彗星实验改良方法及分析参数的可靠性。材料与方法：采用0．3mW／cm^2。UV以用不同时间（3、5、10、40、60、120、180、240S）照射K562细胞，诱导细胞DNA损伤，用彗星实验检测，CASP软件分析。结果：尾长、彗星长、尾矩、Olive尾矩4个参数与紫外线照射时间有良好的时间依赖关系。结论：0．3mW／cm^2的紫外线照射K562细胞3S即可造成细胞DNA损伤，CASP分析软件可以用于彗星检测分析，其中尾长、彗星长、尾矩、Olive尾矩可作为彗星实验的分析指标，所改良的彗星实验系统可靠性较强，且基本上解决了实验中常见的脱胶现象，采图更方便。

英文摘要：

BACKGROUND ＆ AIM： This article exploved a modified method of comet assay from the Singh＇s alkaline comet assay and discussed the reliability of this method and the CASP software used to measure the DNA damage induced by UV light. MATERIAL AND METHODS： DNA damage of K562 cells induced by UV for different times （3 s, 5 s, 10 s,40 s,60 s, 120 s, 180 s,240 s） was measured by comet assay.The results were assayed by CASP. RESULTS： UV （ 0.3 mW/cm^2） induced a significant DNA damage （P 〈 0.01） when the results were assayed by the four parameters （tail length, comet length, tail moment, olive tail moment）. CONCLUSION： The results suggested that the four parameters indicated a good time-dependent effect.The method which we developed and the four parameters were reliable.