Key principles of electron microscopy

Tlie X-ray scattering power of any given atom can be described in terms of the X-ray scattering length of that atom, i x-ray according to the following simple equation  

X-ray crystallography is not the only technique that gives detailed information about molecular architecture. The last decade has seen the remarkable rise of electron microscopy, a 

According to the Abbe relationship, which applies to microscopy, resolution or distance of resolvable separation, d, is related to numerical aperture, NA, and radiation wavelength, X, according to the following relationship  

In the case of an accelerated beam of electrons, p is related to the energy of each accelerated component electron, 0e (i.e. the product of electron charge, e, and electrical potential difference, 0), and the intrinsic particle mass of an electron, m, by 

Nowadays, cryo-electron microscopy, so named for the method of sample preparation and maintenance, is by far the most effective technique of electron microscopy for biological macromolecule characterisation. Therefore, we shall focus on this electron microscopy technique alone from this point onwards. The basis of success in cryo-electron microscopy is very simple though practically quite demanding. A sample of biological macromolecule of interest in water is flash frozen in such a way that individual molecules become embedded 

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