This video demonstrates how to use the microscopes
in the Biology 10 laboratory. It consists of four
parts - setting up the microscope, using the
microscope, troubleshooting hints, and cleanup.
Retrieve a microscope from the cabinet. Carry
the microscope with both hands, one holding
the arm and the other under the base of the
instrument. If the microscope is too heavy
for you to carry safely, ask for assistance.
Unwind the cord from the back of the microscope
and plug it in.
The on/off switch is on the back of the scope,
and may be hard to find if the power cord
is still wrapped around the holders.
Check the ocular lenses and turn them until
the number 64 lines up with the white line
below the rotating part of the lens.
Check that the condenser lens is just below
the stage.
Put the objective lens on low power and move
the stage to its highest position.
Adjust the light to the medium or medium high
range. You can adjust the light later to improve
the image. The brightest light doesn't necessarily
result in the best image.
Now you should be ready to start using the
microscope.
Open the clip on the stage with one hand and
slide a microscope slide to the back of the
stage. Be sure the slide doesn't go under
the clips that hold it in place.
Use the knobs on the lower right side of the
stage to center the specimen over the condenser
lens.
Start with the low power objective lens (4X)
and the stage in its highest position. Then
look through the ocular lens and focus on
the specimen, which should already be nearly
in focus.
Once you have found the specimen on low power,
be sure it is centered in the field of view.
Then move to the next highest objective lens
(10 X) and refocus.
Your specimen should be nearly in focus, and
you should only need to use the smaller, fine-focus
knob.
Again center the specimen and you are ready
to move to the highest power lens (40x).
If your slide doesn't move when you turn the
knobs to adjust the slide holder, make sure
you are using the right knobs and that the
slide is clipped in place properly.
If you are having trouble finding the specimen;
Make sure your specimen is centered
Start over at the lowest power and move the
stage back to its highest position. If you
get frustrated trying to focus, you can easily
get so far out of focus that it is easier
to start over. You should only need to do
minor adjustments at each magnification.
When focusing, move the slide just a little
bit back and forth with the slide holder knobs.
Your eyes can see motion better than stationary
objects
If you are observing unstained specimens,
use the stage diaphragm to reduce the amount
of light passing through.
Also, if you are observing unstained specimens,
try to find a bubble or other easily observed
object under the cover slip and focus on that.
If when you move to a higher power lens, the
specimen becomes blurry as though it were
coated with Vaseline and you cannot focus,
you may need to clean the lens. Soak a piece
of lens paper (and only lens paper) with lens
cleaner and wipe the lens.
Then wipe dry with clean lens paper. Repeat
a couple of times. If this doesn't solve the
problem, check with your instructor.
When you have finished using the microscope,
remove the slide, and rotate the lowest power
lens in place.
Move the stage to a centered position and
slide holder to the left.
Check that the stage is clean and dry.
Turn off the light and power and wrap the
cord.
Carry the microscope with both hands back
to the cabinet. Be sure that the arm is facing
out and that the microscopes are not crowded
together.
