PROTECTANT FOR ELECTRON MICROSCOPE OBSERVATION OF HYDRATED BIOLOGICAL SAMPLE, KIT FOR ELECTRON MICROSCOPE OBSERVATION, METHOD FOR OBSERVATION, DIAGNOSIS, EVALUATION, OR QUANTIFICATION BY ELECTRON MICROSCOPE, AND SAMPLE STAGE
Provided are a protective agent for electron microscopic observation in a vacuum which can protect a biological sample in a water-containing state, such as a mammal, a plant tissue or a cultured cell, and a single cell in the living state without deforming it even in a vacuum, a kit using the same, methods for observation, diagnosis, evaluation, and quantification of a sample by an electron microscope, and a sample stage to be used for the observation. The protective agent for electron microscopic observation of the present invention contains a survival environment imparting component, a saccharide, and an electrolyte.