This video demonstrates how to use the microscopes in Bio 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.