中文摘要：

[目的]利用小分子DNA鉴定重金属离子对DNA的损伤。[方法]将pUC18DNA分子暴露于Hg2＋、Cr6＋、Pb2＋、Cd2＋4种重金属离子环境中,经一定时间处理后对DNA分子进行生物活性研究,并用凝胶电泳和增色效应分析了重金属离子对DNA分子生物活性影响机制。[结果]DNA活性分析表明,4种重金属对pUC18的影响程度为Hg2＋〉Cr6＋〉Pb2＋〉Cd2＋;凝胶电泳和增色效应结果表明,4种重金属离子主要是引起DNA分子交联导致其生物活性的降低,交联程度为Hg2＋〉Cr6＋〉Pb2＋〉Cd2＋。[结论]该研究表明,pUC18DNA分子可用作鉴定重金属离子对DNA损伤的依据,为评价重金属对DNA毒害作用提供了一种简捷有效的技术方法。

英文摘要：

[Objective] The aim was to establish a convenient and effective method to evaluate the toxicity of heavy metal ions by using small molecular DNA. [Method] pUC18 DNA which had exposed to the four heavy metal ions of Hg2＋, Cr6＋, Pb2＋, Cd2＋ was used to study the bioactivity of DNA; simultaneously, gel electrophoresis and hyperchromic effect were employed to detect the mechanism of DNA damage. [Result] The bioactivity of the exposed DNA was decreased and the influence degree was Hg2＋Cr6＋Pb2＋Cd2＋; the gel electrophoresis and hyperchromic effect proved that the main reason leading to reduce the bioactivity was DNA cross link, in the order pf Hg2＋Cr6＋Pb2＋Cd2＋. [Conclusion] The study indicated that pUC18 DNA could be used to assay the damage of DNA causing by heavy mental ions, which may be a potential, simple and effective tool to evaluate toxicity of heavy metal ions to DNA.