Kim Ki Woo
Department of Ecology and Environmental System, Kyungpook National University, Sangju, 37224, Republic of Korea.
Appl Microsc. 2022 May 11;52(1):4. doi: 10.1186/s42649-022-00073-2.
Field emission scanning electron microscopy (FESEM) is an essential tool for observing surface details of specimens in a high vacuum. A series of specimen procedures precludes the observations of living organisms, resulting in artifacts. To overcome these problems, Takahiko Hariyama and his colleagues proposed the concept of the "nanosuit" later referred to as "NanoSuit", describing a thin polymer layer placed on organisms to protect them in a high vacuum in 2013. The NanoSuit is formed rapidly by (i) electron beam irradiation, (ii) plasma irradiation, (iii) Tween 20 solution immersion, and (iv) surface shield enhancer (SSE) solution immersion. Without chemical fixation and metal coating, the NanoSuit-formed specimens allowed structural preservation and accurate element detection of insulating, wet specimens at high spatial resolution. NanoSuit-formed larvae were able to resume normal growth following FESEM observation. The method has been employed to observe unfixed and uncoated bacteria, multicellular organisms, and paraffin sections. These results suggest that the NanoSuit can be applied to prolong life in vacuo and overcome the limit of dead imaging of electron microscopy.
场发射扫描电子显微镜（FESEM）是在高真空环境下观察标本表面细节的重要工具。一系列标本制备程序使得无法观察活的生物体，从而产生假象。为了克服这些问题，Takahiko Hariyama及其同事在2013年提出了“纳米服”的概念，后来被称为“NanoSuit”，它描述的是一种放置在生物体上的薄聚合物层，用于在高真空环境中保护它们。纳米服通过以下方式快速形成：（i）电子束辐照，（ii）等离子体辐照，（iii）吐温20溶液浸泡，以及（iv）表面屏蔽增强剂（SSE）溶液浸泡。在不进行化学固定和金属镀膜的情况下，形成纳米服的标本能够在高空间分辨率下对绝缘、湿润的标本进行结构保存和精确元素检测。形成纳米服的幼虫在FESEM观察后能够恢复正常生长。该方法已被用于观察未固定、未镀膜的细菌、多细胞生物体和石蜡切片。这些结果表明，纳米服可用于延长在真空中的寿命，并克服电子显微镜死成像的限制。
