your Microscope Lenses
The best way to avoid having to clean the
lenses on your microscope is to use it carefully and keep it covered when
not in use. If a lens gets dirty or gummed up, here's what you do.
Only clean your microscope lenses when they are dirty and use the proper materials!
Try to locate the dirt. Is it on the eyepiece
lens or objective lens? If you see a spot when looking in the
microscope and you see it at all powers it's probably on the outside of
the eyepiece lens. If your eyepiece lens turns, turn it and see if
the spot moves. If so, the dirt is on the eyepiece lens. If
the spot doesn't move when you turn the eyepiece lens and you see
it at all powers then the dirt is internal and you should probably have it cleaned by a
professional. If you only see it at one power, the dirt is
most likely on that particular objective lens.
Sometimes all you need to do is blow off the residue. Use a squeeze bulb or one of the camera lens cleaner bulbs with the camel hair brush on the end. If
you need more air pressure, you can use the compressed air cans (like Radio Shack #64-4350). Do
not use any sprays with cleaners. Once blown clean, lightly wipe the lens with
Kimwipes. These are lint-free paper tissue made for use with fine machinery and
optical parts. They are made by Kimberly-Clarke, (who also makes Kleenex), and are
available in art supply and larger paper supply stores among other places.
The proper motion to use when working with these tissues is to
"swipe" the lens in one direction rather than rub in a circular
motion. Do not clean lenses with ordinary cloth, paper towel, or
Another good cleaning tissue is Kodak Lens Tissue (available at photo stores) In lieu of a
brush, you can use the paper. Roll the tissue into a tube and tear it in half, with
the feathery torn ends together. Use it as a one-time brush. Use several for very
dirty lenses. A regular lens brush can hold grit and cause scratching.
If the grime is still there, you will need to use a solvent.
When using solvents, put a drop or two on the paper then hold it against the lens for a few seconds to dissolve
the crud. Then lightly wipe it free. Distilled water is the first solvent
to try. If that doesn't work, try alcohol. Isopropyl alcohol is one of the
best solvents but it must be at least 90%+ pure (do not use rubbing alcohol, 30%
water. Try Walmart for the full strength variety). Everclear which is grain alcohol (you must be 21!) can also be used but it
doesn't do as well in dissolving crud (although it does mix with orange
juice quite well!). If you have something like Balsam stuck on the lens, you must resort to a stronger solvent like
Acetone or Xylene.
Acetone should never be put on plastic parts as it dissolves most paints and plastics.
makes a lens cleaning solution and Edmund Scientific carries one called Lens Luster
Cleaning Fluid. Some people swear by a solution called ROR, although I've never
tried it. You can find it at here.
When adding the solvent, put only a small amount on the kimwipe and always apply it from the underside going upward to the lens. This will
keep the liquid from running down into the lens. Do not remove the lenses from the
instrument unless absolutely necessary and never soak even the tip
of an objective lens in a container of solvent! It could
dissolve the cement used to hold the glass lenses in place.
Sometimes objective lenses get gunked
up with glycerine, blood or other albuminous material. It can be removed with lens paper
dipped in a weak ammonia solution (one dropper full of household ammonia in 1/2 cup water).
If you are using a 100X objective with immersion oil, just
simply "swipe" the excess oil off the lens with a kimwipe after use.
Occasionally dust may build up on the lightly oiled surface so if you wish
to completely remove the oil then you must use an oil soluble
solvent. For the Cargille Type A or B immersion oil, you can
use Naptha, Xylene, or turpentine (use very small amounts on the kimwipe).
Do not use water, alcohol or acetone as the oil is insoluble to these
solvents. Consult the MSDS info that is supplied with your immersion
oil to see what solvents are recommended. To remove other oily substances, we recommend using the
detergent called Wisk and prepare a solution of 1 part Wisk to 100 parts
Periodically inspect the power cords and plugs for safety and have a
replacement bulb available. Professional cleaning and adjusting should be performed whenever necessary at an optical shop specializing in microscopes.
Unless you are a professional do not attempt to clean or adjust the inner
optics of your microscope.
When your microscope is not in use, it should be placed in a case or covered
and stored in a safe area where it won't get knocked over or stolen.
If you have a heavy duty vinyl dust cover, double cover your microscope
with it and a plastic shopping bag. When the dust builds up on the
shopping bag, replace it.