Microscopes are used to magnify objects too small to see with the naked eye. They have various parts including lenses, a stage to hold samples, and adjustments to focus images. There are three main types - simple, compound, and electron - with increasing magnification abilities. Compound microscopes use two lens systems to magnify up to 200x, while electron microscopes can reach 300,000x magnification using electron beams rather than lenses. Microscope users must understand parts, focusing techniques, calculating magnification, and properly preparing and observing slides.

1. T. Trimpe 2005
http://sciencespot.net/

2. MICROSCOPES
• MAGNIFIES OBJECTS (MAKES
OBJECTS LOOK BIGGER)
• HELP SCIENTISTS STUDY
OBJECTS & LIVING THINGS TOO
SMALL TO SEE WITH THE NAKED
EYE

3. Body Tube
Nosepiece
Objectives
Stage Clips
Light
Ocular lens
(Eyepiece)
Arm
Stage
Coarse Adjustment
Fine Adjustment
Always carry a microscope with one hand
holding the arm and one hand under the base.
Base
Diaphragm

4. 3 Types of Microscopes
• simple microscope has only 1 lens.
compound microscope has 2 sets of
lenses. It can magnify things 100 -
200 times larger than they really are.
• electron microscope can magnify
objects up to 300,000 times. They
do not use lenses, but use electrons
to enlarge the image.

5. PARTS OF A MICROSCOPE
1. ocular (lens) eyepiece
• the lens of the microscope that you
look through
2. course adjustment
• the large knob on the microscope
that you turn to bring the object
into focus
3. fine adjustment
• the small knob on the microscope
that brings the image into focus

6. PARTS OF A MICROSCOPE
4. arm
• the part of the microscope
supporting the body tube
5. body tube
• the part that holds the eyepiece and
the objective lenses.
6. nosepiece
• the part at the bottom of the body
tube that holds the objective lenses
and allows them to be turned

7. 7. high power objective lens
• the lens that magnifies the object
the greatest amount. (usually 40x)
8. Low power (scanner) objective lens
• the lens that magnifies the object
the least amount (usually used to find
the object; magnifies only 3x or 4x)
9. middle power objective lens
• the lens that usually magnifies the
object more than the scanner lens,
but less than the high power lens
(usually 10x to 20x)

8. 10. stage
• the flat part below the
objectives lens where the slide
is placed
11. clip
• the part that holds the slide in
place so it doesn’t move
12. diaphragm
• the part that controls the
amount of light entering the
field of view

9. 13. light source
• the lamp (or mirror) under the
stage that sends light through
the object being viewed.
14. base
• the bottom part that supports
the rest of the microscope

10. Body Tube
Nosepiece
Objectives
Stage Clips
Light
Ocular lens
(Eyepiece)
Arm
Stage
Coarse Adjustment
Fine Adjustment
Always carry a microscope with one hand
holding the arm and one hand under the base.
Base
Diaphragm

11. Field of View
• Field of view is the area (circle)
that you see when looking through
the eyepiece

12. Comparing Powers of Magnification
We can see better details with higher the
powers of magnification, but we cannot see
as much of the image.
Which of these images
would be viewed at a
higher power of
magnification?

13. What’s my power?
To calculate the power of magnification, multiply the power of the
ocular lens by the power of the objective.
What are the powers of
magnification for each of
the objectives we have on
our microscopes?
Fill in the table on
your worksheet.

14. Calculating Magnification
1. Find the power of the lens. It is found on
the side of the lens. Magnification power of
a lens is always identified by the label of x
(10x, 1000x)
2. Multiply the power of the eyepiece by the
power of the objective lens.
3. Examples:
eyepiece obj. lens
10x times 100x
10x times 50x
10x times 40x

15. Appearance of the Specimen
• Objects appear upside-down &
backward
• Movement appears to be in opposite
direction than actual movement 1
2
move slide
slide appears to move
2 1

16. Let’s give it a try ...
1 – Turn on the microscope and then rotate the nosepiece to click the
red-banded objective into place.
2 – Place a slide on the stage and secure it using the stage clips. Use
the coarse adjustment knob (large knob) to get it the image into view
and then use the fine adjustment knob (small knob) to make it
clearer.
4 – When you are done, turn off the microscope and put up the
slides you used.
3 – Once you have the image in view, rotate the nosepiece to view it
under different powers. Draw what you see on your worksheet!
Be careful with the largest objective! Sometimes there is
not enough room and you will not be able to use it!

17. Recording Observations
• Draw specimen large enough to fill
“field of view” circle
• Draw as many details as possible
• Drawing should be neat
• Label specimen
• Label power of magnification
• Name & date on paper

18. Making a Wet Mount Slide
1. Use dropper to place a drop of
water on the center of a clean slide.
2. Use tweezers to lay specimen on
the drop of water.
3. Gently touch the cover slip to the
edge of the drop of water to cover
the specimen & the water.

19. How to make a wet-mount slide …
1 – Get a clean slide and coverslip from your teacher.
2 – Place ONE drop of water in the middle of the slide. Don’t use
too much or the water will run off the edge and make a mess!
3 – Place the edge of the cover slip on one side of the water drop.
You do not need to use the stage clips
when viewing wet-mount slides!
5 – Place the slide on the stage and view it first with the red-banded
objective. Once you see the image, you can rotate the nosepiece to
view the slide with the different objectives.
4 - Slowly lower the cover slip on top of the drop.
Cover
Slip
Lower slowly