Guénebaut V, Maaloum M, Bonhivers M, Wepf R, Leonard K, Hörber J K
European Molecular Biology Laboratory (EMBL), Heidelberg, Germany.
Ultramicroscopy. 1997 Sep;69(2):129-37. doi: 10.1016/s0304-3991(97)00042-9.
A subtle combination of constant current and constant height modes in scanning tunnelling microscopy allowed the imaging of a non-flat uncoated biological specimen, namely the tail of the bacteriophage T5. In parallel, a reference three-dimensional structure of the T5 tail was calculated from cryo-transmission electron microscopy images, based on its helical symmetry. This three dimensional reconstruction was compared with scanning tunnelling microscopy data. The images of the tail obtained by transmission electron microscopy, as well as projections of the reconstructed model, show similar moiré patterns. Here we show that scanning tunnelling microscopy performed in an aqueous environment provides direct images which are remarkably similar to the projection of the three dimensional model obtained by transmission electron microscopy. We deduce that our scanning tunnelling microscopy images are the result of a transmission of electrons through the gap between the scanning tip and the conductive support across the biological specimen.
扫描隧道显微镜中恒流模式和恒高模式的巧妙结合，使得对未镀膜的非扁平生物样本（即噬菌体T5的尾部）进行成像成为可能。与此同时，基于T5尾部的螺旋对称性，从冷冻透射电子显微镜图像中计算出了其三维参考结构。将这种三维重建结果与扫描隧道显微镜数据进行了比较。通过透射电子显微镜获得的尾部图像以及重建模型的投影显示出相似的莫尔条纹图案。在此我们表明，在水环境中进行的扫描隧道显微镜能够提供与透射电子显微镜获得的三维模型投影非常相似的直接图像。我们推断，我们的扫描隧道显微镜图像是电子通过扫描探针与导电支撑物之间的间隙穿过生物样本的结果。
