高效毛细管电泳用于以聚环氧乙烷为筛分介质分离DNA的机理研究

Mechanism of the DNA Separation with High Performance Capillary Electrophoresis in Poly(ethylene oxide) Matrix

用毛细管电泳以聚环氧乙烷(PEO)为筛分介质对pUC19DNA/Msp Ⅰ(HpaⅡ)Marker中的12条DNA片段进行了分离,并尝试用Ogston模型、爬行模型以及线性模型对分离机理进行研究,最终发现26～147bp的小片段,在低电场强度时能很好地符合Ogston模型理论,而190～501bp中等长度的DNA片段电泳迁移率与其尺寸间存在很好的负相关的线性关系,为此,提出一种新的线性模型来进行解释.此外,还探讨了PEO的浓度和电场强度对分离的影响.其结论可更好地从理论上指导对中小片段DNA的分离,对肿瘤基因突变点的分析和PCR扩增产物的分离分析具有重要的意义.

The 12 segments of pUC19 DNA/MspⅠ（HpaⅡ） marker have been separated and theoretical explanation was provided.The results gave better insight into the mechanisms of separations in polymer solutions.The dependence of different parameters on DNA size,electric field and the polymer concentration was evaluated and explained.Ogston model and a linear model were used to explain the behavior of 26～147 bp DNA fragment at lower electric field intensity.But,a new linear model was established in our experiment,which included the negative linear relation of electrophoretic mobility with DNA size.It could explain the separation mechanisms of 190～501 bp DNA fragment.The data should help to optimize and direct the small and medium DNA molecule separation in capillary electrophoresis and have a great sense in analysis of the mutational site of the tumor and the product of PCR.