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 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: microscope.htm microscope.htm