Argaman M, Golan R, Thomson N H, Hansma H G
Department of Physics, University of California, Santa Barbara, CA 93106, USA.
Nucleic Acids Res. 1997 Nov 1;25(21):4379-84. doi: 10.1093/nar/25.21.4379.
Phase imaging with a tapping mode atomic force microscope (AFM) has many advantages for imaging moving DNA and DNA-enzyme complexes in aqueous buffers at molecular resolution. In phase images molecules can be resolved at higher scan rates and lower forces than in height images from the AFM. Higher scan rates make it possible to image faster processes. At lower forces the molecules are imaged more gently. Moving DNA molecules are also resolved more clearly in phase images than in height images. Phase images in tapping mode AFM show the phase difference between oscillation of the piezoelectric crystal that drives the cantilever and oscillation of the cantilever as it interacts with the sample surface. Phase images presented here show moving DNA molecules that have been replicated with Sequenase in the AFM and DNA molecules tethered in complexes with Escherichia coli RNA polymerase.
使用轻敲模式原子力显微镜（AFM）进行相成像在以分子分辨率对水性缓冲液中的移动DNA和DNA - 酶复合物进行成像方面具有许多优势。在相图像中，与AFM的高度图像相比，分子可以在更高的扫描速率和更低的力下得到分辨。更高的扫描速率使得对更快的过程进行成像成为可能。在较低的力下，分子成像更为轻柔。移动的DNA分子在相图像中也比在高度图像中分辨得更清晰。轻敲模式AFM中的相图像显示了驱动悬臂的压电晶体的振荡与悬臂与样品表面相互作用时的振荡之间的相位差。这里呈现的相图像展示了在AFM中用测序酶复制的移动DNA分子以及与大肠杆菌RNA聚合酶结合成复合物的拴系DNA分子。
