Electroconductive Pretreatment of Several Types of Non-conductive Wet Biological Samples for SEM using a Room Temperature Ionic Liquid: Simple and Rapid Conductive Preparation

72 Introduction A room temperature ionic liquid (RTIL) is an organic salt that is liquid at room temperature and has specific physical properties such as noncombustibility, no vapor pressure, high heat resistance, and high ionic conductivity. These unique properties have led many researchers to use RTILs in various fields, including electronics, chemistry, analysis, and catalysis [1-6]. Kuwabata et al. have reported the successful use of an RTIL for the electronic pretreatment of biological samples, such as insects, flowers, tissues, pollen, and cells, for scanning electron microscopy (SEM). As RTILs have high electrical conductivity and no or very low vapor pressure, they can maintain their liquid state even in vacuum, making them suitable for use inside an SEM sample chamber, and also facilitate clear Electroconductive Pretreatment of Several Types of Non-conductive Wet Biological Samples for SEM using a Room Temperature Ionic Liquid: Simple and Rapid Conductive Preparation