在寻求圣杯“看到”单个分子如何在液体环境中相互作用的过程中,单分子成像方法现在包括液相电子显微镜,其分辨率可以是纳米的空间和几帧每秒的时间使用普通的电子显微镜,这是常规的许多研究人员。然而,以目前的艺术水平,听起来类似于文献中描述的协议导致可能不同的结果。关键挑战是在足以捕获分子过程的帧速率内,在安全电子剂量下实现样品对比度。这里,我们提供了来自不同系统的这些例子——合成聚合物,脂质组装,DNA酶-我们已经使用石墨烯液体细胞做到了这一点。我们描述了详细的实验程序,并分享了进行成功实验的经验,从制造石墨烯液体电池开始,从理想的形状和尺寸中识别高质量的液体袋,为了在电子显微镜下有效搜索目标样品袋,并区分样品分子和感兴趣的分子过程。这些实验技巧可以帮助希望使用这种方法的其他人。
In quest of the holy grail to \"see\" how individual molecules interact in liquid environments, single-molecule imaging methods now include liquid-phase electron microscopy, whose resolution can be nanometers in space and several frames per second in time using an ordinary electron microscope that is routinely available to many researchers. However, with the current state of the art, protocols that sound similar to those described in the literature lead to outcomes that can differ. The key challenge is to achieve sample contrast under a safe electron dose within a frame rate adequate to capture the molecular process. Here, we present such examples from different systems─synthetic polymer, lipid assembly, DNA-enzyme─in which we have done this using graphene liquid cells. We describe detailed experimental procedures and share empirical experience for conducting successful experiments, starting from fabrication of a graphene liquid cell, to identification of high-quality liquid pockets from desirable shapes and sizes, to effective searching for target sample pockets under electron microscopy, and to discrimination of sample molecules and molecular processes of interest. These experimental tips can assist others who wish to make use of this method.