Positively Charged Nanogold Label Allows the Observation of Fine Cell Filopodia and Flagella in Solution by Atmospheric Scanning Electron Microscopy
Positively Charged Nanogold Label Allows the Observation of Fine Cell Filopodia and Flagella in Solution by Atmospheric Scanning Electron Microscopy
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DOI：
10.1002/jemt.22322
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发表时间：
2014-02-01
影响因子：
2.5
通讯作者：
Sato, Chikara
中科院分区：
文献类型：
--
作者：
Nishiyama, Hidetoshi;Teramoto, Kanae;Sato, Chikara
光学显微镜通常是观察微生物和细胞的首选。然而，它的分辨率并不总是足以揭示特定的目标结构，如鞭毛和菌毛，它们只有纳米宽。ASEM是一个有吸引力的更高分辨率的替代方案，因为样品是在大气压的水溶液中观察到的。亚欧会议的样品前处理只包括固定、金标记和试剂交换等简单操作，总共只需不到1小时。更经典的电子显微镜通常需要进行冗长的样品前处理，如包埋和脱水，这是不必要的，并且保留了原始的形态。在这项研究中，带正电荷的纳米金颗粒被用来标记细菌和培养的动物细胞的表面，利用它们的净表面负电荷。在金增强以增加纳米金颗粒的大小后，ASEM对水溶液中细菌的成像显示了菌毛和精致的螺旋鞭毛。这一自然形状与标准扫描电子显微镜记录的干燥鞭毛图像形成鲜明对比。带正电的纳米金标记在培养的COS7细胞的质膜上，增强后可以清楚地显示直径为100 nm的丝状足细胞。在这些研究的基础上，ASEM结合带正电的纳米金标记有望在不久的将来成为研究细胞形态和动力学的重要工具。Microsc.技术资源。2014年，77：153-160。(C)2013年威利期刊公司。
Optical microscopy is generally the first choice to observe microbes and cells. However, its resolution is not always sufficient to reveal specific target structures, such as flagella and pili, which are only nanometers wide. ASEM is an attractive higher resolution alternative, as the sample is observed in aqueous solution at atmospheric pressure. Sample pretreatment for ASEM only comprises simple tasks including fixation, gold labeling, and reagent exchange, taking less than 1 h in total. The lengthy sample pretreatments often required for more classical electron microscopies, such as embedding and dehydration, are unnecessary, and native morphology is preserved. In this study, positively charged nanogold particles were used to label the surfaces of bacteria and cultured animal cells, exploiting their net negative surface charge. After gold enhancement to increase the size of the nanogold particles, ASEM imaging of the bacteria in aqueous solution revealed pili and delicate spiral flagella. This natural shape contrasts starkly with images of dried flagella recorded by standard SEM. Positively charged nanogold labeled the plasma membrane of cultured COS7 cells, and after enhancement allowed filopodia as thin as 100 nm in diameter to be clearly visualized. Based on these studies, ASEM combined with positively charged nanogold labeling promises to become an important tool for the study of cell morphology and dynamics in the near future. Microsc. Res. Tech. 77:153-160, 2014. (c) 2013 Wiley Periodicals, Inc.