Student microscopes are optical tools that are used by students and scientists to get a magnified view of very small objects or details. There are several types of microscopes, however, for students the most commonly used type is a basic compound light microscope. This type of microscope is call “compound” because it utilizes two lenses to magnify the objects on a slide. A compound light microscope is appropriate for examining cells, organisms and inorganic materials. Many science fair projects require the use of a compound microscope. A compound light microscopes work by shining a light through a condenser lens which is placed between the light source and the specimen tray. The image is then transmitted through the body tube and through the projector lens and finally to the eyepiece. To use a microscope you first prepare a slide, which is a small glass plate. To prepare a slide you will place a drop of water in the center of the slide and then add the cell or organism to be viewed in the water drop. You will then use a thin piece of glass or plastic to press down the specimen and keep it in the center of your slide.
Next you will place the slide under the slide clips, which are found on the stage of the microscope. This will secure your slide. Make sure that your specimen is positioned directly over the aperture. Now you will turn on your light source and select the objective lens that you want. Make sure your body tube is high enough so that the objective lens that you select doesn’t crack or come into contact with your slide. Utilize your coarse and fine adjuster knobs to bring your specimen image into focus. Another option that you have for bringing out fine details in an organism or specimen is to use the oil immersion lens process. In this process you will create a wet mount slide like you did before. Then you will move the objective lenses so that no lens is snapped into position. Next you will place a small drop of oil on top of the cover slip.
Then you will snap the 100X objective lens into place, which will bring it into contact with the oil. Use the fine adjuster knob to bring the objective lens up about 1mm from the slide cover slip. Next continue to adjust the fine adjuster knob until your image has been brought into focus. Arm: The arm of the microscope is the metal or plastic handle shaped protrusion that connects the nose pieces/body tube configuration and it also acts as the carrying handle for the microscope. Body Tube: The body tube is the container that houses the objective lenses which magnify the specimen image. At the top of the body tube sites the eyepiece. Coarse Adjustment Knob: The course adjustment knob is found on the side of the microscope. You use this knob to focus your magnified image. This knob focuses the image by moving the body tube/nose piece configuration up and down. Diaphraghm: The diaphraghm is the device that is used to control how much light is allowed through the aperture, or the hole in the stage.
Eye Piece: The eye piece is the portal to the image and where you look to see the image of what is on your slide. Fine Adjustment Knob: The fine adjustment knob is also found on the side of the microscope. However, this knob is used to fine tune the focus of the image of your specimen. Light Source: The light source is found at the base of the microscope. Most student microscopes will have an electric lamp as the light source, however, there are a few more basic models that uses mirrors to capture and focus light from external sources through the aperture. Nose Piece: The nose piece is found at the bottom of the body tube. You manipulate this piece to select the objective lens magnification that you are interested in. Objective Lenses: Objective lenses are the tube-like lens heads that are found at the bottom of the body tube.