Difference between Compound and Electron Microscope

Light Microscope

Difference between Compound (Light) and Electron Microscope: The simple student’s microscope which is often used in schools is called compound microscope. In these microscopes many lenses combined together and their magnification power range from 300 to 1500 times. These microscopes use light (generally sunlight) to illuminate the object, so these compound microscopes called light microscopes. Let us try to get acquainted with various parts of a light microscope. The object or specimen on a glass slide kept on a stage under an objective piece (having lenses) almost in the middle of the microscope.

Light is passed through the object/specimen with the help of a mirror (called reflector) and a condenser from below the stage. From the eyepiece on the top one can see a magnified image of the object/specimen. A sharp image forms by focusing the side knobs properly. The upper and large knob meant for coarse adjustments. Used for rapid and precise focusing of the object. The lower and small knob used for fine adjustments (i.e., for getting perfect image of the object). The magnification of an image can increased or decreased by changing the objectives of high or low power (5 X, 10 X, 15 X, etc.) accordingly.

Electron Microscope

An electron microscope is a very large instrument that uses electromagnets for magnification and electrons for illumination. This remarkable instrument developed by Knoll and Ruska of Germany in 1932. It was put to use in 1940. It uses very high voltage electricity. Electron microscope helps in observing subcellular structures which cannot be seen through a compound microscope. An internal vacuum is essential for its working. The object must be ultra thin and dry. Electron microscope impregnated with some metal to enhance contrast. The image of the object obtained on a photographic film or screen. Magnification is 100,000 to 500,000.