Transcript Microscope Basics

T. Trimpe 2005
http://sciencespot.net/
Ocular lens
(Eyepiece)
Body Tube
Nosepiece
Arm
Objective lenses
Stage
Stage Clips
Diaphragm
Coarse adjustment focus knob
Fine adjustment focus knob
Light
Base
Always carry a microscope with one hand holding the arm and
one hand under the base.
Name of Part
Description
Function
Eyepiece (ocular)
lens
Flat bottom surface
Holds the slide in place, letting light
pass through it
Objective lens
Flat surface to sit slides on, has hole
in its centre, may have clips
Adjusts the position of the lenses so
that the object can be seen clearly; can
be coarse or fine
Focus knob
Iris-like aperture that can be adjusted
to allow light through
Light travels through it to the eyepiece
lens
Base
Knob that can be turned to move the
lenses
Controls the amount of light passing
through the object
Mirror
The adjustable tube between the
eyepiece and objective lenses
Supports the microscope
Stage
Lenses of different focal lengths that
can be positioned above the slide
Reflects light up through the slide into
the lenses
Diaphragm
Round with a shiny surface
Used to get different magnifications
Microscope tube
Single lens closest to the eye
Bends the light to make the object look
bigger
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.
Comparing Powers of Magnification
We can see better details with higher
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?
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.
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 and put up the
slides you used.
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!