用AFM对质粒DNA在云母表面的自组装研究

Self-assembly behavior of plasmid DNA on the surface of mica studied with atomic force microscope

通过原子力显微镜(AFM)对在云母表面上自然挥干的不同质量浓度的质粒DNA分子进行扫描,原子力显微镜图像显示:当质量浓度为0 1μg/mL时,DNA分子呈现出线性结构,随着质量浓度加大至1μg/mL,DNA分子相互缠绕为网状结构,质量浓度为10μg/mL时,呈现出具有典型的聚合形态,当质量浓度进一步加大到100μg/mL,则呈现出明显的树状脉络结构.通过原子力显微镜对质粒DNA分子的形态表征,可以看出质粒DNA分子具有典型的自组装的特性.

Plasmid DNA at certain concentrations on mica were scanned by noncontact mode atomic force microscope. Linear topography was observed when plasmid DNA were at a concentration of 0.1 μg/mL. It was found to present a three-dimensional network on mica when at a concentration of 1 μg/mL and typical aggregate topography when at a concentration of 10 μg/mL. When the concentration reached 100 μg/mL, it showed tree-like structures. Typical self-assembly characteristic of plasmid DNA molecules on mica was observed by atomic force microscope.