Transmission electron microscopy (TEM) is an ideal device to study the internal structure of cells and different types of biological materials, but adverse conditions inside electron microscopes such as damage induced by electron bombardment and vacuum evaporation of structural water necessitates complex preparation methods to survive this environment. In order to introduce the sample into the evacuated microscope column, it should be stabilized and altered to small enough (about 3 mm in diameter) and thin enough parts to permit the transmission of electrons. Depending on applications different thicknesses are required; for example, in biological research studies usually 300-500 nm thickness is indicated. To stabilize the specimen and preserve the sample structures, different preparation methods are used involving different steps based on the type of study and the specimen, although the ultimate goal of all these preparation technics is to maintain the native structure of the sample. In this chapter, we try to explain the series of steps that involve in preparation. Virtually every step can affect the quality of sample, and therefore it is important to execute each step in detail.
Keywords: Fixation; High pressure freezing; Protocol; Sample preparation; TEM.