A modified ‘NanoSuit®’ preserves wet samples in high vacuum: direct observations on cells and tissues in field-emission scanning electron microscopy

• Published in: Royal Society open science 2017-03, Vol.4 (3), p.160887-160887
• Main Authors: Takaku, Yasuharu, Suzuki, Hiroshi, Kawasaki, Hideya, Ohta, Isao, Ishii, Daisuke, Hirakawa, Satoshi, Tsutsui, Takami, Matsumoto, Haruko, Takehara, Sayuri, Nakane, Chinatsu, Sakaida, Kana, Suzuki, Chiaki, Muranaka, Yoshinori, Kikuchi, Hirotoshi, Konno, Hiroyuki, Shimomura, Masatsugu, Hariyama, Takahiko
• Format: Article
• Language: English
• Subjects: Biochemistry And Biophysics; Field-Emission Scanning Electron Microscope (fe-Sem); high vacuo; Living Specimen; Nanosuit; Surface Shield Effect
• ISSN: 2054-5703; 2054-5703
• DOI: 10.1098/rsos.160887

Although field-emission scanning electron microscopy (FE-SEM) has proven very useful in biomedical research, the high vacuum required (10−3 to 10−7 Pa) precludes direct observations of living cells and tissues at high resolution and often produces unwanted structural changes. We have previously described a method that allows the investigator to keep a variety of insect larvae alive in the high vacuum environment of the electron microscope by encasing the organisms in a thin, vacuum-proof suit, the ‘NanoSuit®'. However, it was impossible to protect wet tissues freshly excised from intact organisms or cultured cells. Here we describe an improved ‘NanoSuit' technique to overcome this limitation. We protected the specimens with a surface shield enhancer (SSE) solution that consists of glycerine and electrolytes and found that the fine structure of the SSE-treated specimens is superior to that of conventionally prepared specimens. The SSE-based NanoSuit affords a much stronger barrier to gas and/or liquid loss than the previous NanoSuit did and, since it allows more detailed images, it could significantly help to elucidate the ‘real' organization of cells and their functions.