Biology
USING A MICROSCOPE
Aims:
 Distinguish and label the parts of a microscope
 Describe the function of the parts of a microscope
 Use a microscope to make and record observations
Agenda:
 Parts of Microscope
 How to Use a microscope notes
 Introduction to the Light Microscope
 Observations
Development
Parts of Microscope
 Explain to students the proper way to carry a microscope
 Have students distribute microscopes and packets
 Students read packet and use packet to label parts
 Review parts on OH
 Oral Quick Quiz
How to Use Microscope
 Students read and complete notes as each step is demonstrated
 Emphasize importance of using only fine knob with medium and high power when applicable
 Students practice without slide and explain as they go
Introduction to Light microscope
 Explain that scanning power also means low power in packet, low is medium, high is high
 Students work in pairs to complete packet using letter E slides and general bio slides
Assessment: Students explain to middle school students how to use a microscope
Homework: Study for CAPT
Biology
USING A MICROSCOPE
Do Now
1. Identify each statement as True or False. If False, correct the statement.
 There could be many communities within a population.
 An ecosystem consists of living and nonliving things in a certain area.
 Cells are smaller than molecules.
 Tissues are smaller than organs.
 Producers eat consumers.
2. Which of the following includes the other three?
 Tissue
 Organelle
 Cell
 Organ
3. Describe a community one might find in an aquarium.
Biology
USING A MICROSCOPE
Directions: Carefully read and annotate the information below.
Compound microscopes Use multiple lenses (unlike the single lens of a simple microscope) to
produce an increase in magnification. If the eyepiece lens enlarges by a factor of 10 (10X) and the
objective lens enlarges by a factor of 40 (40X), the total magnification is the product of the two 400X.
Parts of a Compound Light Microscope

Eyepiece (Ocular): Usually contains a 10X lens.

Arm: contains the housing for the fine and
coarse adjustments and connects the base
of the microscope to the nosepiece and
ocular.

Nosepiece: A rotating head that has the
objective lenses attached to it. The lens to
be used should "click" into position when the
wheel is gently turned so that it is directly
over the specimen slide.

Objective: Holds a lens. Most high school
microscopes have three objective lenses 4X, 10X, and 40X (low, medium, high power).

Stage: The specimen slides rests on this part
of the microscope.

Coarse adjustment knobs: The larger of two
sets of knobs located on either side of the
arm, just above the base. This adjustment is used to make large adjustments in focusing by
moving the lenses up and down. Never use this adjustment when using the 40X objective.

Fine adjustment knobs: The smaller of two sets of knobs located on either side of the arm. This
adjustment is used to make small adjustments in focusing. It has a limited amount of
movement and is most efficiently used after focusing with the 4X objective and coarse focus.

Light source: Located directly under the stage.

Adjustable diaphragm: This rotating wheel on the underside of the stage allows the user to
adjust the amount of light that passes through the specimen. As a general rule, use the lowest
intensity of light that allows you to resolve the structure of the object you are viewing.
Care and Handling of the Lab Microscopes

A microscope is a delicate piece of equipment and should be treated with care.

Use two hands when carrying the microscope. Place one hand around the arm of the
microscope and the other under the base for support.

Carry the microscope upright and close to the body.

Place the microscope flat on the table, but not too near the edge.

If it becomes necessary to clean the lenses on the microscope, ask your facilitator for a piece
of lens paper. Other materials, such as paper towel, can scratch the surface of the lens.
Biology
USING A MICROSCOPE
Cleanup:

If using a wet mount slide, wipe the sample and coverslip off the slide with a paper
towel when finished.

Throw the paper towel and its contents away.

Return the microscope slide to its container.

Always rotate the nosepiece so that the LOW POWER objective lens is in line with the
eyepiece.

Cover the microscope and return the microscope to storage.
Viewing Specimens Under a Microscope
On the stage
Through the lens

Because the microscope uses lenses and mirrors, the
image you see through most light microscopes will be
upside down and backward.

In most instances, light must pass through any object
to be viewed with a light microscope. For this reason,
the object must be fairly thin. Thick objects must be
sliced into thin sections for viewing.

Never view a slide without a coverslip. The coverslip protects the objective lens from the
liquid on the slide.

Many objects do not have distinct, contrasting colors. This makes seeing details difficult.
Observation may be improved by staining with a biological stain.
Drawing Objects:
When making drawings on your lab report, do the following:

For drawings only, use a pencil - you can erase and
shade areas.

Begin by identifying the area viewed through the
microscope with a circle.

Specimens should be drawn to scale. If the specimen
takes up the whole viewing field, make sure your
drawing shows this.

Drawings should be labeled with the specimen name and magnification.

Drawings should be large enough to view details and have significant details labeled.

All labels should be written on the outside of the circle.
Biology
USING A MICROSCOPE
Reviewing Microscope Basics
Label each part of the microscope and give a two-word description of its function.
1.
Why is the microscope above known as a compound microscope? Why is this an advantage?
2.
The eyepiece of a microscope is 10x and the objective lens is 30x. What is the magnification of
an object viewed under this microscope?
3.
Draw how the following letter would appear in a microscope:
4.
Why must the specimen on a slide be thin?
5.
A student carries a microscope to her table with two hands, places it flat on the table away
from the edge, and locates a specimen with a cover slip under high power using the coarse
adjustment knob. What mistake did the student make?
6.
A student draws the following observation in his lab notebook. What mistake did he make?
F
Biology
USING A MICROSCOPE
How to Use a Microscope
1. Always carry the microscope with one hand holding the _______ and one hand holding the _____.
2. Plug in the microscope and turn on the _________ ________________.
3. Raise the ____________ as far as possible.
4. Place the slide on the ________________ and ____________ the slide over the opening in the stage.
5. Rotate the ______________ so that the ____________________________ is in place.
6. While looking through the ___________________, slowly turn the ___________________________ until the
slide is in focus.
7. Slowly move the slide to __________________ the specimen.
8. Adjust the _______________________ to get the best lighting.
9. Switch to the ________________ power objective. Refocus using the ______________________ and
__________________ the specimen again if necessary.
10. Switch to the _____________ power objective. Refocus using the ________________________ only and
_________________ the specimen again if necessary.
Data Sheet: Microscopic Observations
Name of Cell _______________________
What special features – shape, size, etc- does this cell have?
_________________________________________________________________________________________________
How might this relate to its function?
_________________________________________________________________________________________________
Biology
USING A MICROSCOPE
Data Sheet: Microscopic Observations
Name of Cell _______________________
What special features – shape, size, etc- does this cell have?
_________________________________________________________________________________________________
How might this relate to its function?
_________________________________________________________________________________________________
Name of Cell _______________________
What special features – shape, size, etc- does this cell have?
_________________________________________________________________________________________________
How might this relate to its function?
_________________________________________________________________________________________________
Biology
USING A MICROSCOPE
Data Sheet: Comparing Human Cells
Name of Cell _______________________
Is this cell prokaryotic or eukaryotic? How do you know?
_________________________________________________________________________________________________
How might this relate to its function?
_________________________________________________________________________________________________
Name of Cell _______________________
What special features – shape, size, etc- does this cell have?
_________________________________________________________________________________________________
How might this relate to its function?
_________________________________________________________________________________________________
Biology
USING A MICROSCOPE
Exit Slip
1. Based on your experience in the lab today, what are the three most important tips to using a
microscope successfully?
2. Label the parts of the microscope below from memory and give a brief description of each
part’s function.