Lyubchenko Y L, Gall A A, Shlyakhtenko L S, Harrington R E, Jacobs B L, Oden P I, Lindsay S M
Department of Physics, Arizona State University, Tempe 85287.
J Biomol Struct Dyn. 1992 Dec;10(3):589-606. doi: 10.1080/07391102.1992.10508670.
A procedure for imaging long DNA and double stranded RNA (dsRNA) molecules using Atomic Force Microscopy (AFM) is described. Stable binding of double stranded DNA molecules to the flat mica surface is achieved by chemical modification of freshly cleaved mica under mild conditions with 3-aminopropyltriethoxy silane. We have obtained striking images of intact lambda DNA, Hind III restriction fragments of lambda DNA and dsRNA from reovirus. These images are stable under repeated scanning and measured contour lengths are accurate to within a few percent. This procedure leads to strong DNA attachment, allowing imaging under water. The widths of the DNA images lie in the range of 20 to 80nm for data obtained in air with commercially available probes. The work demonstrates that AFM is now a routine tool for simple measurements such as a length distribution. Improvement of substrate and sample preparation methods are needed to achieve yet higher resolution.
本文描述了一种使用原子力显微镜（AFM）对长链DNA和双链RNA（dsRNA）分子进行成像的方法。通过在温和条件下用3-氨丙基三乙氧基硅烷对新劈开的云母进行化学修饰，实现双链DNA分子与平坦云母表面的稳定结合。我们获得了完整的λ噬菌体DNA、λ噬菌体DNA的Hind III限制性片段以及呼肠孤病毒的dsRNA的清晰图像。这些图像在重复扫描下稳定，测量的轮廓长度精确到百分之几以内。该方法能使DNA牢固附着，可在水下成像。使用市售探针在空气中获得的数据显示，DNA图像的宽度在20至80纳米范围内。这项工作表明，AFM现在是进行诸如长度分布等简单测量的常规工具。要实现更高的分辨率，还需要改进底物和样品制备方法。
