The energy filtering TEM (EFTEM) in modern biological transmisson Electron Microscopy

Abstract

Modern biological electron microscopy can no longer be a static tool merely describing morphology. In addition to ultrastructural information, insights into the molecular and chemical composition of a sample are needed so that new findings stemming from molecular biological and biochemical analyses can be given meaning in an ultrastructural context. Biological electron microscopy will be an essential tool for future discoveries involving the ultrastructural localization of molecules and chemical elements, and it will provide a means to identify the ultrastructural basis for a variety of reaction mechanisms. Many messenger compounds are currently known which can produce dynamic changes of either a subtle or dramatic nature at the ultrastructural level, but only the most basic of these can be examined using a conventional transmission electron microscope (CTEM). CTEMs provide limited information because they perform conventional imaging and do not employ all the signals available for analysis. Unlike a CTEM, an EFTEM permits the selection of a defined energy (wavelength) of electrons which are then used for imaging.