用原子力显微镜表征DNA纯化效果的实验研究

Identification of DNA purification effect by atomic force microscopy

目的:运用原子力显微镜(AFM)表征3种DNA纯化试剂盒对DNA的纯化效果。方法:PCR扩增K562/A02细胞mdr1基因DNA,分别以3种不同的DNA纯化试剂盒对PCR产物进行纯化后,按终浓度为10 ng.μl-1固定在用1 ng.μl-1L型多聚赖氨酸预先处理过的新剥离的云母片上,用AFM获取DNA扫描图像,分析评价3种DNA试剂盒对DNA的纯化效果。结果:用AFM成功表征3种纯化试剂盒纯化后DNA片段,获得了清晰的DNA图像。对3种DNA纯化试剂盒的纯化效果作出评价,建议其中的两种DNA纯化试剂盒的DNA纯化产物可用于AFM的DNA分析。结论:用AFM表征DNA时对DNA的纯度要求较高。通过对3种DNA纯化试剂盒纯化效果的比较,为AFM观测DNA样本的纯化方法提供了较好的方案。

Objective To identificate purification effect of three kinds of DNA purification kits by atomic force microscopy（ AFM ）. Methods Cuhivateion and PCR technique was used to amplify K562/A02 cells with DNA of mdrlgene. The amplified products were purified by three kinds of DNA purification kits, a final concentration of 10 ng ·μl^ -1 DNA samples were placed on a freshly cleaved mica treated by 1 ng · μl^ -1 L-polylysine. AFM was used for the imaging of the three pieces of DNA samples. Results Through AFM image analyzing, the purification effect of three kinds of DNA purification kits was evaluated, two kits can be used to purify DNA samples for AFM imaging. Conclusion The higher the purify of DNA sample used, the better the AFM image got. Two better purification schemes have been achieved for DNA imaging using AFM through comparing three kinds of DNA purification kits.