Microscopes
What is this?
I. Parts of the Compound Light
Microscope
Metal or plastic part on which microscope rests
BASE
Somewhat C-shaped pillar arising from the
base and supports the stage and ocular
components. Used for carrying
ARM
Flat platform attached to lower portion
of arm on which slides or samples are
STAGE
Collects light rays and focuses them
on the specimen slide. Can be
adjusted for better resolution (sharper
image)
DIAPHRAGM
Convex lens used to magnify the image;
generally 10-15x magnification
Ocular or eyepiece
Small convex lenses screwed into
nosepiece and increase the magnification
of the sample.
Low power = 4x
high power =40x
OBJECTIVES
Larger knob which moves the base rapidly up or
down to get the sample into coarse focus
COARSE ADJUSTMENT KNOB
Smaller knob which moves the base slowly
through short distances to get the sample into
sharp focus
FINE ADJUSTMENT KNOB
REMEMBER:
 All specimens must be thin for LIGHT to shine through
them so that you can see clearly.
REMEMBER
 Only use the FINE ADJUSTMENT
KNOB when focusing on medium or
high power objectives!!
 This avoids damaging or breaking
the slide
Electron microscope
 Electron microscope – a microscope
that focuses beams of electrons
instead of light rays. Produces
clearer, 3D images.
Muscle Tissue!
LIGHT MICROSCOPE VS.
ELECTRON MICROSCOPE
LIGHT
MICROSCOPE
ELECTRON
MICROSCOPE
I. USED TO VIEW LIVING
OBJECTS
II. COLOR AND
MOVEMENT CAN BE
OBSERVED
I. OBJECTS CANNOT BE
ALIVE
II. BLACK AND WHITE
IMAGES WITH NO
MOVEMENT
III. POOR RESOLUTION
III. EXCELLENT
RESOLUTION
IV. VIEWER MUST BE
TRAINED/VERY
EXPENSIVE
IV. EASY TO
USE/INEXPENSIVE
Calculating magnification
 Just multiply the objective lens power by the ocular
lens power
 Lower power: 10 X 4= 40
 Medium power: 10 x10= 100
 High power: 10x40=400
• Instructions:
Guided Practice
You will be using your fingers to show me the correct answer
for the following questions
We are going to read the question SILENTLY. DO NOT CALL
OUT THE ANSWER.
Think about the question and pick an answer.
When I count to 3, You are going to hold up your choice.
DO NOT LOOK AT ANYONE ELSE’S ANSWER!! THIS IS
YOUR TIME TO FIGURE OUT IF YOU KNOW THE
INFORMATION!
QUESTION 1
1. One advantage of using a light microscope is that it –
A. has high resolution
B. magnifies clearly to 1000x
C. can be used to view living cells
D. can be used to view atoms
QUESTION 1
1. One advantage of using a light microscope is that it –
A. has high resolution
B. magnifies clearly to 1000x
C. can be used to view living cells
D. can be used to view atoms
QUESTION 2
2. When you are focusing on medium or high power
objectives, you should use the
A. Coarse knob adjustment
B. Fine knob adjustment
C. Ocular
D. Diaphargm
QUESTION 2
2. When you are focusing on medium or high power
objectives, you should use the
A. Coarse knob adjustment
B. Fine knob adjustment
C. Ocular
D. Diaphargm
Question 3
The purpose of the diaphragm is to
A. Adjust the amount of light focusing on the specimen
B. Magnify the specimen on the stage
C. Adjust the magnification of the specimen
D. View the specimen on the stage
Question 3
The purpose of the diaphragm is to
A. Adjust the amount of light focusing on the specimen
B. Magnify the specimen on the stage
C. Adjust the magnification of the specimen
D. View the specimen on the stage
Question 4
If a microscope’s ocular is marked 10x and the low power
objective is marked 4x, what would be the total
magnification when using the low power objective?
A. 10x
C. 40x
B. 12x
D. 400x
Question 4
If a microscope’s ocular is marked 10x and the low power
objective is marked 4x, what would be the total
magnification when using the low power objective?
A. 10x
C. 40x
B. 12x
D. 400x
Question 5
If a microscope’s ocular is marked 10x and the low power
objective is marked 30x, what would be the total
magnification when using the low power objective?
A. 3x
B. 300x
C. 30x
D. 3000x
Question 5
If a microscope’s ocular is marked 10x and the low power
objective is marked 30x, what would be the total
magnification when using the low power objective?
A. 3x
B. 300x
C. 30x
D. 3000x
Question 6
One disadvantage of using an electron microscope is that
it
A. has high resolution
B. Very expensive
C. shows details of the surface
D. can be used to view atoms
Question 6
One disadvantage of using an electron microscope is that
it
A. has high resolution
B. Very expensive
C. shows details of the surface
D. can be used to view atoms
Worktime
1. How should you carry a microscope?
2. What knob should you use to focus when
using a high power objective?
3. Why should you not use the coarse knob
adjustment when using the high power
objective?
Worktime
1.
How should you carry a microscope?
2.
What knob should you use to focus when using a high power objective?
3.
Why should
you not use the coarse knob adjustment when using the high power objective?
4. What is the purpose of the
diaphragm?
5. Where is the ocular lens located?
6. Where are the objective lens located
7. What is the purpose of the stage?
8.
If the ocular lens has a magnification of 10x and the objective lens has a
magnification of 25x, what is the total magnification?
9.
If the ocular lens has a magnification of 4x and the objective lens has a
magnification of 50x, what is the total magnification?
1.
How should you carry a microscope?
2.
What knob should you use to focus when using a high power objective?
3.
Why should you not use the coarse knob adjustment when using the high power objective?
4.
What is the purpose of the diaphragm?
5.
Where is the ocular lens located?
6.
Where are the objective lens located
7.
What is the purpose of the stage?
Worktime
8. If the ocular lens has a magnification of 10x and the
objective lens has a magnification of 25x, what is the
total magnification?
9. If the ocular lens has a magnification of 4x and the
objective lens has a magnification of 50x, what is the
total magnification?
10.If the ocular lens has a magnification of 5x and the
objective lens has a magnification of 100x, what is
the total magnification?
Exit Ticket:1
1) I used to work at an Air force base. We would work
with particles of metal called nano particles. The
particles were dead, and microscopic. What would be
the best way to see those?
a) A light microscope
b) An electron scanning microscope
c) A light telescope
d) An electron scanning teloscope
Exit Ticket 2:
2) When the low power objective is being used you should
adjust it using the:
a) fine adjustment knob
b) diaphragm
c) course adjustment knob
d) ocular adjustment knob
Exit Ticket 3
3) Which of the following statements is NOT true about
objects viewed with an electron scanning microscope?
A. They must be thin enough to allow light to pass
through them.
B. They must be living specimens
C. No dyes or states can be used on the objects
D. They must be made of organic material
Exit Ticket 4
4) If the microscopes ocular lens is marked 10x and the
lower power objective is marked 5x, what is the total
magnification?
a) 10
b) 5
c) 50
d) 500
Exit Ticket: 5
5) What is the proper way to place a cover slip on a wet
mount slide?
a)
c)
b)
d)