Abstract
For observation of aquatic micro-organisms by a scanning electron microscope, sample pretreatments are necessary to avoid the deformation of cell membrane by evaporation of moisture from inside of the cell in vacuum and also the charging-up of sample under irradiation of electron beam. In the present paper, we report on a simple preparation method by ethanol dehydration and the ionic liquid coating method without using any apparatus for preparation such as a refrigerator, a vacuum equipment and etc.