T. Trimpe 2005
http://sciencespot.net/
Body Tube
Ocular lens
(Eyepiece)
Nosepiece
Objectives
Arm
Stage
Stage Clips
Coarse Adjustment
Diaphragm
Light
Fine Adjustment
Base
Always carry a microscope with one hand
holding the arm and one hand under the base.
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.
Lab Expectations
• Treat the microscope with respect, it is an
expensive piece of scientific equipment.
• If you are unsure of how to do something,
ask! Do not “force” the microscope lenses
into position.
• Look at the chart, what needs to be filled in?
• What is the best way to approach this task?
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?
What happens to our
view of an image as you
increase the power or
magnification? (Hint: 2
things)
Lab Expectations
• Treat the microscope with respect, it is an
expensive piece of scientific equipment.
• If you are unsure of how to do something,
ask! Do not “force” the microscope lenses
into position.
• You will be working with glass – breaking
hazard!
• If at any point you are not following lab
expectations, you will be asked to stop the
lab.
Lenses
• What is different about the length of each
lens?
• So, why can’t you use the largest objective
for some slides?
Be careful with the largest objective! Sometimes there is
not enough room and you will not be able to use it!
How to use a microscope
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.
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!
4 – When you are done, turn off the microscope.
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.
4 - Slowly lower the cover slip on top of the drop.
Cover
Slip
Lower slowly
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.
You do not need to use the stage clips
when viewing wet-mount slides!
What you might find:
Metapus
Amoeba
Paramecium
Didinium
Pond Water Procedures and Clean Up
Before:
1. Get a slide and cover sheet from me.
2. Pick up the sample of pond water (in a small cup) and a
dropper.
3. One person will make the slide, and the others in the
group will view that same slide once it is made.
4. Follow the instructions on your page.
After:
5. Another person in the group will clean off the slide
(carefully – it is glass) and the cover sheet.
6. I will have a place on the front lab table to place these.
7. Place the prepared amoeba slide back on the stage, under
the clips – CAREFULLY!
Amoeba Video:
http://videoserver.magnet.fsu.edu/micro/pondscum/protozo
a/amoeba/mpeg/amoeba01df40x.mpg