Download Care and Use of the Compound Microscopes

Care and Use of the
Compound Microscopes
Moorpark College
Biology Department
Care and Use of the Compound
Microscopes
• Ten things to consider when
storing a microscope
• How to adjust the microscope for
your eyes
• Tips on the microscope
Ten things to consider when
storing a microscope
• These ten items for consideration are not
in any order or importance or sequence.
• These are the minimal steps to take care
of our microscopes, which are excellent
when they are well cared for.
• Think of your use of the microscope as a
new professional skill.
#1 Remove slides from stage
• #1 Remove slides from stage.
– Be sure to place the prepared slides in
their correct tray. Look at the label of
the slide and the label of the edge of
the tray.
– Wet mounts should be rinsed by you
and the cover slips and slides placed in
the labeled beakers.
#2 Rheostat set to lowest level
• #2 Rheostat (or power level) is set at zero
or lowest setting.
• Why?
– If the microscope is turned on with the
rheostat at the highest level a surge of energy
can blow the light bulb.
– Bulbs cost $25 each!
#3 Store the microscope in its
proper cabinet
• The number on the bottom of the arm will
have a room and cabinet number (220-52, for
room LMC 220 and cabinet 52).
• Why is this important?
–To keep track of the
microscopes, to determine
which are being repaired or
borrowed and not stolen!
Always place it in the correct
cabinet.
#4 Cover
• #4 Cover with a
plastic bag or cover.
• Why?
– To protect it from dust.
These are very
expensive and
sensitive pieces of
equipment and we
want them to work well
for you.
#5 Clean the Microscope
• #5 Clean the Microscope
• How?
– Lens paper and glass cleaners for the lenses
only! Don’t forget the eyepieces, too. Although
oil should only be used with the 100X
objective it often gets onto the 40X objective
lens and stage as well.
– Kimwipes can be used to clean the stage and
other parts of the microscope.
#6 Power is off
• #6 Power is off.
• Why is this important?
If someone plugs in
the microscope and
the power is on, the
surge of electricity
can blow-out the
halogen lamp. Each
lamp costs more than
$25!
#7 Lowest power objective
• #7 Lowest power objective in
place.
• Why? One reason is to prevent
the stage from accidentally
crashing into the objective lens.
• The other reason is that when
you begin to use the microscope
you must (should) always start
with the lowest magnification.
This is the best technique and
prevents lens damage.
#8 Arm facing out
• #8 Place microscope in cabinet
with arm facing out.
• Why?
– So that the next student can easily remove it
from the cupboard.
– Also the head piece of the microscope can be
loosened and if the microscope is placed in
the cupboard backwards it may be grabbed
by the headpiece and the bottom dropped!
#9 Wrap power cord
• #9 Wrap power cord around the base of the
microscope.
• Tip. Don’t wrap it too tight! The wire inside the
power cord can break inside the plastic covering if
it is stressed too much.
#10 Lock it up
• #10 Lock it up.
• Why? We don’t want to lose them, they’re
very expensive.
• Don’t forget to return the key to the front of
the room or lab cart. If you discover you
accidentally pocketed the key – just bring
it back ASAP.
How to adjust the microscope for
your eyes
• If the microscope is not adjusted for your eyes,
your brain will try to merge the two images,
which may result in a headache or dizziness.
• Remove glasses and adjust the microscope
for your eyes without
them, then:
– Adjust for interpupillary
distance
– Adjust for diopter
Adjust for interpupillary distance
• After a slide is focused at a low setting relax at a
comfortable distance from the eyepieces.
• Move the ocular lenses together and apart until
one clear image merges together.
• Note your interpupillary distance on the
microscope. Refocus and readjust for the
diopter.
• Don’t forget to continue to
readjust this distance.
Adjust for diopter
• This will let you adjust the
microscope for your two eyes.
– Focus the microscope on a specimen.
– Cover the left eye and adjust the fine focus knob on
one spot in the field of view.
– Cover the right eye and turn the left ocular lens until
the same spot in the field of view is in sharp focus.
– Observe with both eyes, adjust interpupillary distance
until one clear image merges together.
Microscope use tips
• Always change the
objective lenses by
the knurled nose ring.
When the objective
lenses are used to
change power, they
are ever so slightly
loosening and
damaging their thread
mounts. To work their
best all lenses must
be aligned perfectly.
Microscope use tips
• Always begin examining a
new slide at the lowest power
possible.
• Use the coarse focus knob
only with the 4X objective lens
to get the first level of focus,
then only use the fine focus
knob with the higher power
lenses. The working distance
is so tiny it is very easy to
scratch a lens and break a
slide at the same time.
Microscope use tips
• Videos of proper microscope use:
http://biology.clc.uc.edu/Courses/bio111/
microscope.htm