The basics of transmission electron microscopy
Transmission electron microscopy is a powerful imaging technique that uses an electron beam instead of light to image biological samples. In a TEM setup, an electron beam passes through an ultrathin section of a sample and interacts with the sample. The electrons that pass through the sample are collected on the other side and converted into an image that shows the internal structures of cells in unprecedented detail.
To achieve optimal results, biological samples must be carefully prepared. Typically, samples are fixed, dehydrated and embedded in a resin matrix to obtain ultra-thin sections (about 50-100 nanometres) that can be easily penetrated by the electron beam.