Microscopes are instruments used to see objects too small to be seen by the naked eye.There are three major types of microscope that a biologist/researcher uses. These are the electron, dissecting and compound microscopes. Within the category of electron microscope are two types of microscope, the Scanning Electron Microscope and the Transmission Electron Microscope.
One of the oldest types of microscopes, the optical microscope has been around since the 1600’s. Often referred to as a light microscope, this microscope consists of a light source and several lenses used to magnify small objects. There are two types of light microscopes, the simple and the compound.
The simple microscope uses only one lens for magnification while the compound uses multiple. The compound microscope contains lenses which allow for the focusing of the light to the observer’s eye. The main advantage of the compound microscope is its ability to allow for a greater resolution for viewing a specimen. This type of microscope also has an eyepiece which generally has a magnification of ten and when combined with high power objective lenses makes it possible to magnify an object up to 400 times.
The dissecting microscope is a microscope which allows for close observation for the dissecting of specimens, sorting or microsurgery. The dissecting microscope allows for light to be reflected from the object to your eye instead of the other way around in light microscopy. A dissecting microscope allows for the viewing of specimens which may be too thick for a regular compound microscope.
A Scanning Electron Microscope uses a high energy electron beam. The electrons react with the atoms that make up the sample, in particular the atoms that are near the samples surface. The images seen with this type of microscope are three dimensional and although this type of microscope can have an objective lens, its main purpose is the focus an electron beam on the specimen. Pictures from this type of lens are generally black and white. A Scanning Electron Microscope can magnify from 10 to 500,000 times, or about 250 times that of a typical light microscope.
A Transmission Electron Microscope is another type of microscope where specimens are viewed after being hit with an electron beam. With this type of microscope, the beam reacts with the specimen and the image is reflected and magnified to a new imagine device. The Transmission Electron Microscope allows for a specimen to be examined in greater detail, allowing it to have a much higher resolution that your typical compound microscope.