MODEL RELEASED. Cancer research. Researcher using a transmission electron microscope (TEM) to study a cancer cell (on screen). She is studying growth factor receptors using antibodies designed to attach to the receptors. The antibodies are joined to gold particles (black dots) so that they are easily identifiable on the micrograph. A TEM uses a beam of electrons to make an image of a sample. The beam is propelled towards the sample down a column. After passing through the sample the electrons are detected and used to form an image.