Electron microscopy

The resolution of a light microscope (0.2 pm) is ultimately limited by the wavelength of light. Many biological molecules and subcellular components are too small for that resolution to reveal, and their structures were shown only by the development of the electron microscope. Electrons have a shorter wavelength than light, improving resolution to 0.2-0.5 nm and allowing magnifications up to many thousand times. A transmission electron microscope (TEM) uses electrons focused by electromagnetic lenses, producing an image observed on a fluorescent screen and recorded digitally or photographically.

TEM has many uses in physics, of course, but biological materials pose special …