Specimen preparation chemical fixation

Despite the high power of the electron microscope, which achieves resolutions of the order of 3 A, i.e. molecular resolution, the reliability of the method has been questioned in the past. These doubts especially involve the possibility of electron-beam damage and the shortcomings of the preparation techniques. The latter involve chemical fixation, dehydration and staining which might interfere or even disturb the native structure. The development of adequate preparation methods is therefore of utmost importance for high resolution electron microscopy of biological specimens. This has been realized from the early days of electron microscopy. 

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