Abstract

The unique ability of electron microscopy in biology is its power to describe and integrate structural details down to molecular dimensions within the context of a complex living system.  The information density provided from an EM investigation is determined by the hierarchy of the steps involved in specimen preparation and imaging. The structural complexity of a living biological system can only be preserved as a whole. It can not be investigated in the linear analytical way characteristic of biochemistry or electrón microscopy of isolated samples, because these techniques can only physiologically control simplified systems. Structural information closely related to the living state may therefore become an indispensable tool to intégrate the analytical findings. It can be achieved by cryoimmobilisation techniques that vitrify the cellular water and at the same time rapidly arrest all physiological processes