Re: oil immersion lens cleaning

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From:"Barry Rittman" <> (by way of Marvin Hanna)
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Oil on the front surface of the objective lens while it is non-drying does two
things. First it attracts and retains dirt particles. Second and perhaps more
important is that the oil can be carried over, both from the oil immersion
lens to
the slides to be examined without oil, and also there can be carryover from
oil on
the surface of the cover glass. This is especially a problem when switching
and forwards between oil immersion and dry 40x objective lenses.
It its therefore good practice to at least remove excess oil using lens tissue,
Kimwipes etc. as suggested.
The discussion regarding the various cleaners  to use. The main point is to
use any
solvent in moderation. Desppite the comments, xylene is fine to use and
will not
destroy the cement of the lens unless excessive amount is used and/or
allowed to
stay on the lens surface. Should not be cheapskate with regard to using
plenty of
lens tissue etc. and removing all traces of solvent.
Many years ago the xxxxxx microscope representative for Iowa said that he
used soft
expanded polystyrene pieces to remove most of the excess oil from the
surface. If
oil residue remained, ether with lens tissue was used to wipe the surface.
I personally, use lens tissue and moderate amounts of lens cleaner (which
mostly isopropyl alcohol and small amont of acetone) and moderate amounts
of xylene
if any oil residue remains.

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