Peckys Diana B, de Jonge Niels
1 Leibniz Institute for New Materials (INM), 66123 Saarbrücken, Germany.
Microsc Microanal. 2014 Apr;20(2):346-65. doi: 10.1017/S1431927614000099. Epub 2014 Feb 19.
Scanning transmission electron microscopy (STEM) of specimens in liquid, so-called Liquid STEM, is capable of imaging the individual subunits of macromolecular complexes in whole eukaryotic cells in liquid. This paper discusses this new microscopy modality within the context of state-of-the-art microscopy of cells. The principle of operation and equations for the resolution are described. The obtained images are different from those acquired with standard transmission electron microscopy showing the cellular ultrastructure. Instead, contrast is obtained on specific labels. Images can be recorded in two ways, either via STEM at 200 keV electron beam energy using a microfluidic chamber enclosing the cells, or via environmental scanning electron microscopy at 30 keV of cells in a wet environment. The first series of experiments involved the epidermal growth factor receptor labeled with gold nanoparticles. The labels were imaged in whole fixed cells with nanometer resolution. Since the cells can be kept alive in the microfluidic chamber, it is also feasible to detect the labels in unfixed, live cells. The rapid sample preparation and imaging allows studies of multiple whole cells.
对液体中的样本进行扫描透射电子显微镜（STEM）观察，即所谓的液体STEM，能够对液体中完整真核细胞内大分子复合物的各个亚基进行成像。本文在细胞的先进显微镜技术背景下讨论这种新的显微镜技术。描述了其工作原理和分辨率方程。所获得的图像与通过标准透射电子显微镜获得的显示细胞超微结构的图像不同。相反，对比度是通过特定标记获得的。图像可以通过两种方式记录，一种是在200 keV电子束能量下使用包围细胞的微流体腔室进行STEM成像，另一种是在30 keV下对处于潮湿环境中的细胞进行环境扫描电子显微镜成像。第一系列实验涉及用金纳米颗粒标记的表皮生长因子受体。这些标记在完整的固定细胞中以纳米分辨率成像。由于细胞可以在微流体腔室中保持存活，因此在未固定的活细胞中检测这些标记也是可行的。快速的样品制备和成像使得对多个完整细胞的研究成为可能。
