title: A 'NanoSuit' surface shield successfully protects organisms in high vacuum: observations on living organisms in an FE-SEM.
abstract: Although extremely useful for a wide range of investigations, the field emission scanning electron microscope (FE-SEM) has not allowed researchers to observe living organisms. However, we have recently reported that a simple surface modification consisting of a thin extra layer, termed 'NanoSuit', can keep organisms alive in the high vacuum (10(-5) to 10(-7) Pa) of the SEM. This paper further explores the protective properties of the NanoSuit surface-shield. We found that a NanoSuit formed with the optimum concentration of Tween 20 faithfully preserves the integrity of an organism's surface without interfering with SEM imaging. We also found that electrostatic charging was absent as long as the organisms were alive, even if they had not been coated with electrically conducting materials. This result suggests that living organisms possess their own electrical conductors and/or rely on certain properties of the surface to inhibit charging. The NanoSuit seems to prolong the charge-free condition and increase survival time under vacuum. These findings should encourage the development of more sophisticated observation methods for studying living organisms in an FE-SEM.
authors: Department of Biology, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu 431-3192, Japan CREST, Japan Science and Technology Agency, Hon-cho 4-1-8, Kawaguchi 332-0012, Japan.
authors: Yasuharu
authors: Y
authors: Takaku
authors: Department of Chemistry, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu 431-3192, Japan.
authors: Hiroshi
authors: H
authors: Suzuki
authors: Laboratory for Ultrastructure Research, Research Equipment Center, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu 431-3192, Japan.
authors: Isao
authors: I
authors: Ohta
authors: Department of Biology, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu 431-3192, Japan.
authors: Takami
authors: T
authors: Tsutsui
authors: Department of Biology, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu 431-3192, Japan.
authors: Haruko
authors: H
authors: Matsumoto
authors: Departments of Bio- and Material Photonics, Chitose Institute of Science and Technology, 758-65 Chitose, Hokkaido 066-8655, Japan CREST, Japan Science and Technology Agency, Hon-cho 4-1-8, Kawaguchi 332-0012, Japan.
authors: Masatsugu
authors: M
authors: Shimomura
authors: Department of Biology, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu 431-3192, Japan CREST, Japan Science and Technology Agency, Hon-cho 4-1-8, Kawaguchi 332-0012, Japan hariyama@hama-med.ac.jp.
authors: Takahiko
authors: T
authors: Hariyama
mesh_terms: D033304:Amphipoda / Q000648:ultrastructure; D000818:Animals; D001517:Coleoptera / Q000648:ultrastructure; D003465:Culex / Q000648:ultrastructure; D004553:Electric Conductivity; D008855:Microscopy, Electron, Scanning / Q000379:methods*; D011136:Polysorbates; D013499:Surface Properties; D014618:Vacuum
chemical_list: D011136:Polysorbates
keywords: NanoSuit; field emission scanning electron microscope; high vacuum; living organism; surface shield effect
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