MMG 301 Study Guide - Final Guide: Scanning Electron Microscope, Transmission Electron Microscopy, Gram Staining

• School: MSU
• Department: Microbio & Molecular Genetics
• Course: MMG 301
• Professor: N.Hammer

Document Summary

Phase contrast/dic brings direct and reflected or diffracted light rays together to form an image of the specimen on the ocular lens; facilitate detailed examination of the internal structures of living specimens. (3d) Fluorescence uses an ultraviolet source of illumination that causes fluorescent compounds in a specimen to emit light. Transmission electron microscope (tem) uses a beam of electrons instead of light; electrons pass through the specimen; 2-d image; to examine viruses or the internal ultra structure in thin sections of cells. Scanning electron microscope (sem) uses a beam of electrons instead of light; electrons are reflected from the specimen; 3-d image; to study the surface features of cells and viruses. 10,000x (20nm) (peq): explain how electron microscope methods (tem & sem) differ from light microscopy. Instead of light, a beam of electrons is used with an electron microscope. Instead of class lenses, electromagnets control focus, illumination, and magnification.