[Obtaining distinct images of biological forms with the raster electron microscope]

Not only fixation of material, but also conditions of studying it in the raster electron microscope influence the quality of the image. In case the carbon or the heavy metal layer is thin there is danger during rapid scanning of charging the sample by the electron beam, the quality of the image thus becoming worse. It is best to study the biological samples at the two nominals of the accelerating voltage (for example, 10 and 4 kV); this permits to avoid mistakes in interpretation of the results. Neither the thickness of the carbon or the heavy metal layer not the different nominals of the accelerating voltage could influence the value of the information obtained if analysis with consideration to the physical basis of the image formation and experimental conditions were conducted in each individual case. The archives material fixated in common formalin can be used for the study in the raster electron microscope.