Microscopes, Electron, Scanning/Transmission
Definition : Electron microscopes designed to combine the characteristics of transmission electron microscopes (TEMs) and scanning electron microscopes (SEMs) in one instrument. These microscopes include an electron gun and vacuum chamber, an electromagnetic condenser and electromagnetic imaging (lens) systems, a specimen chamber, a viewing chamber and fluorescent screen, photographic and vacuum systems, and a scanning system. Before observation, tissue samples must be prepared according to the technique to be performed (i.e., transmission or scanning), including fixation, embedding, and sectioning; additional preparation for scanning microscopy may be needed (e.g., gold coating of samples). The clinical uses of combined electron microscopes include visualization of tissue, individual cells, and cell structure; identification of cancer cells; diagnosing and differentiating types of renal diseases; and gathering information on hematologic disorders and biological surfaces (e.g., small intestines, serous cavities).
Entry Terms : "STEMs" , "Transmission/Scanning Electron Microscopes" , "Scanning/Transmission Electron Microscopes"
UMDC code : 18091