Before to start exploring the parts in a microscope need to know what is a microscope and why it is used.
Definition of a microscope:
We can not see everything through with our naked eyes. Microscope is lab equipment or a device which is used to classify items that are too small to be seen by the naked eye. We can simply say that a microscope used to magnify a small object or to get clear information about a larger object.
Types of Microscopes:
There are various types of microscope used in modern life. They are given below in the table.
|Types of Microscopes||Description|
|Compound Microscopes||Compound microscopes are light illuminated. The image seen with this type of microscope is two dimensional. This microscope is the most commonly used. You can view individual cells, even living ones. It has high magnification. However, it has a low resolution.|
|Dissection or Stereoscope||A dissection microscope is light illuminated. The image that appears is three dimensional. It is used for dissection to get a better look at the larger specimen. You cannot see individual cells because it has a low magnification.|
|Confocal Microscope||This microscope uses a laser light. This light is used because of the wavelength. Laser light scan across the specimen with the aid of scanning mirrors. Then image is then placed on a digital computer screen for analyzing.|
|Scanning Electron Microscope (SEM)||SEM use electron illumination. The image is seen in 3-D. It has high magnification and high resolution. The specimen is coated in gold and the electrons bounce off to give you and exterior view of the specimen. The pictures are in black and white.|
|Transmission Electron Microscope (TEM)||TEM is electron illuminated. This gives a 2-D view. Thin slices of specimen are obtained. The electron beams pass through this. It has high magnification and high resolution.|
Parts of a microscope labeled below in the picture:
How to Use a Microscope
All of the parts of a microscope work together. The eyepiece, Diopter Adjustment, Body tube (Head), Arm, Coarse adjustment, Fine adjustment, Nosepiece, Objective lenses, Specimen or slide, Stage, On/off switch, Iris diaphragm, Base everything helps to work properly.
- Turn the revolving turret (2) so that the lowest power objective lens (eg. 4x) is clicked into position.
- Place the slide on the stage (6) and fasten it with the stage clips.
- Look at the objective lens (3) and the stage from the side and turn the focus knob (4) so the stage moves upward. Move it up as far as it will go without letting the objective touch the coverslip.
- Look through the eyepiece (1) and move the focus knob until the image comes into focus.
- Adjust the condenser (7) and light intensity for the greatest amount of light.
- Move the microscope slide around until the sample is in the centre of the field of view (what you see).
- Use the focus knob (4) to place the sample into focus and readjust the condenser (7) and light intensity for the clearest image (with low power objectives you might need to reduce the light intensity or shut the condenser).
- When you have a clear image of your sample with the lowest power objective, you can change to the next objective lenses. You might need to readjust the sample into focus and/or readjust the condenser and light intensity. If you cannot focus on your specimen, repeat steps 3 through 5 with the higher power objective lens in place. Do not let the objective lens touch the slide!
- When finished, lower the stage, click the low power lens into position and remove the slide.
- Your microscope slide should be prepared with a coverslip over the sample to protect the objective lenses if they touch the slide.
- Do not touch the glass part of the lenses with your fingers. Use only special lens paper to clean the lenses.
- Always keep your microscope covered when not in use.
- Always carry a microscope with both hands. Grasp the arm with one hand and place the other hand under the base for support.