Transmission Electron Microscopy

Electron microscopy uses electrons rather than photons, and magnetic lenses rather than glass lenses, to image a sample. The result is a magnification up to 250 times that of a light microscope.

The transmission electron microscope images extremely thin samples by passing a beam of electrons through the sample. The sample is often impregnated with heavy metals, which assist in scattering the electrons and thus produce contrast. Alternatively, the sample can be imaged by cryo-TEM methods, which maintains a more natural state of the sample but reduces contrast and the signal-to-noise ratio.

Samples that are commonly imaged on the TEM are virus and protein spray preparations and thin sections (70-200 nm) of samples that have been cut on a microtome. Elemental dispersive spectroscopy (EDS) and electron tomography are also available on the TEM in Bioimaging.