Learning to Use the
Microscope
Introduction
"Micro" refers to tiny while "scope" refers to view or look at. Microscopes are tools used to
enlarge images of small objects so they can be studied. Microscopes range from a simple
magnifying glass to the expensive electron microscope. The compound light microscope is the
most common instrument used in education today. It is an instrument containing two lenses,
which magnify, and a variety of adjustment knobs to resolve (focus) the picture. It is a rather
simple piece of equipment to understand and use. In this lab, we are going to learn the proper
use and handling of the microscope.
Objectives
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Demonstrate the proper procedures used in correctly using the compound light
microscope.
Prepare and use a “fun” slide using an index card and scotch tape (specimen is students
choice).
Materials
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Compound light microscope
Index cards (cut in half) with hole punch in the middle
Scotch tape
Scissors
Post it Notes
Pen/Pencil
Proper Handling of the Microscope
1. Carry the microscope with both hands --- one on the arm and the other under the base of
the microscope.
2. Make sure to turn off the light source any time the microscope is not in use.
3. When finished, always:
 Turn off the light source
 Lower the stage using the coarse adjustment knob
 Remove the specimen slide
 Turn the objective lens to the lowest power (shortest) objective lens.
Getting Acquainted with your Microscope:
Now it is time to get acquainted with your microscope using the following instructions. You
can work with a partner for this.
 Get 4 post-it Notes
 Cut so there are three equal size strips. Make sure each strip has a sticky part.
 Label each strip with a part of the microscope listed below.
 One person places the labeled post-its on the corresponding parts of the
microscope while the other person uses their notes to check for accuracy.
 When the first person can correctly label all the parts it is time to switch roles.
Eyepiece
Arm
Nosepiece
Objective lenses
Stage
Stage clips
Diaphragm
Coarse Adjustment
Fine Adjustment
Base
Light Source
LET’S REVIEW: Answer the following questions about using the microscope:
1. What is the proper way to carry a microscope?
2. When should you avoid using the coarse focus knob? Why?
3. What should you use to clean the lens if it is dirty?
Preparing a “fun” slide and examining specimen under the microscope.
1. Get an index card “slide” with a hole in the middle.
2. Place a piece of scotch tape on the bottom, covering the hole.
3. Find a specimen in the classroom that you would like to examine under the microscope.
(ex. piece of thread, piece of hair, dust, dead bug, etc.)
4. Place the specimen over the hole on the index card.
5. Cover the specimen with another piece of scotch tape.
6. Label your slide with your initials and class period.
7. Use the coarse adjustment knob to lower the stage to the lowest possible position.
8. Turn the nosepiece so that the lowest power objective lens (the shortest one) clicks into
place in the direction of the stage.
9. Place your slide on the stage of the microscope and move the stage clips over the edges of
your “slide” to hold it in place.
10. Turn on the light for the microscope. (Switch is on the base).
11. Open the diaphragm to allow the maximum amount of light to reach the specimen.
12. While looking through the eyepiece, raise the stage using the coarse adjustment knob
until the specimen comes into focus.
13. Adjust the diaphragm as necessary to allow more or less light to reach the specimen.
What specimen are you examining? __________________________
Draw a picture and describe what you see under the lowest objective lens:
14. Turn the nosepiece so that the medium objective lens (the medium size) clicks into place
in the direction of the stage.
15. While looking through the eyepiece, use the fine adjustment knob until the specimen is
in clearest focus.
16. Adjust the diaphragm as necessary to allow more or less light to reach the specimen.
Draw a picture and describe what you see under the medium power objective lens:
17. Turn the nosepiece so that the high power objective lens (the largest) clicks into place in
the direction of the stage.
18. While looking through the eyepiece, use the fine adjustment knob until the specimen
comes into focus. BE CAREFUL WHEN ADJUSTING. YOU DO NOT WANT THE
LENS TO TOUCH THE SPECIMEN. ADJUST SO THAT IT IS CLOSE TO BUT NOT
TOUCHING THE SPECIMEN.
19. Adjust the diaphragm as necessary to allow more or less light to reach the specimen.
Draw a picture and describe what you see under the high power objective lens:
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Mystery Slide Challenge: If time permits, try to identify unknown specimens on
the slides labeled as follows:
Slide A: _______________________________
Slide B: _______________________________
Slide C: _______________________________
Slide D: _______________________________