Microscopes

     Microscopes are devices that produce magnified images of structuresthat are too small to see with the unaided eye. Light microscopes produce magnified images by focusing visible light rays. Electron microscopes produce magified images by focusing beams of electrons. The most commonly found microscope is the compound light microscope. These allow light to pass through the specimen and use two lenses to form an image. Light microscopes make it possible to study dead organisms and their parts, and to observe tiny organisms and cells while they are still alive. To study smaller objects, scientists use electron microscopes. Electron microscopes use beams of electrons to produce images instead of light. They can produce images up to 1000 times more detailed than a light microscope. There are two main types of electron microscopes: Scanning electron microscopes and Transmission electron microscopes. Scanning electron microscopes scan a narrow beam of electrons back and forth across the surface of a specimen. Transmission electron microscopes shine a beam of electrons through a thin specimen. SEM's create three dimensional images of the surfaces of objects, where TEM's produce images of the inside of objects. Both electron microscopes operate in a vacuum to produce their images, so specimens must be dehydrated and preserved before an image can be taken. We will also use dissecting scopes to view larger items. The magnification on these is 20-30x.

Here are some images taken with various microscopes (light, SEM, TEM, dissecting)