Atomic force microscopy (AFM) enables determination of physical properties from single DNA molecules. Insertion of aromatic molecules into the structure of DNA results in morphological changes. However, the accompanying changes to elastic properties due to this insertion are not fully understood. AFM was used to examine the morphological effects of intercalator binding and report changes in the elastic properties of intrinsically straight DNA molecules. The persistence length and polymer extension were characterized in the presence of three intercalating molecules: ethidium bromide and the less well studied chloroquine and acridine. It was found that all three intercalators significantly increased the bending persistence length. In addition, an analysis of the normal bending modes of the static molecules corroborated these results. This approach of measuring binding effects of intercalators on DNA physical properties using a model system of intrinsically straight DNA is applicable to other DNA binding ligands and other modes of DNA interaction.

中文翻译：

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嵌入分子对DNA聚合物特性的影响。

原子力显微镜（AFM）能够确定单个DNA分子的物理性质。芳香分子插入DNA结构会导致形态变化。然而，由于这种插入而导致的伴随弹性特性的变化还没有被完全理解。原子力显微镜用于检查嵌入剂结合的形态学影响，并报告内在直链DNA分子弹性特性的变化。在三个插入分子的存在下，对持久性长度和聚合物延伸进行了表征：溴化乙锭和研究较少的氯喹和and啶。发现所有三个嵌入剂均显着增加了弯曲持久性长度。另外，对静态分子正常弯曲模式的分析证实了这些结果。