I haven’t read the method that we train
our users to follow so I’ll toss it into the mix.
(this is generally for inverted
microscopes – upright stands don’t have to worry about leaving oil
on the objective as much because they will generally not collect as much dust
and cannot run down into the objective itself or on the microscope – for an
upright just wiping the excess oil off and cleaning occasionally is usually
sufficient)
Three things are needed:
1) a box (not an envelop – a box) of lens tissue, Specifically
the Ross 4 ¼” x 5”. There are 1000 sheets per box and with daily
use by many users each box lasts a good long time. Reason for the box? If
there is going to be debris from the air falling on it the underside will
always be clean. Since you pull a fresh piece off each time providing only the
underside touches the objective lens you greatly reduce the risk of scratching
it. I abhor the booklets. People never pull sheets out in order, invariably
someone touches both sides of the tissue to remove it, using them to clean
objectives gives me chills.
2) Puritan Cotton Tipped applicators (single end). Yes the long
wooden applicators. These come in nice paper packages, when opened at the wood
end the cotton side stays hidden and protected. The longer reach (than say a
cotton swab) makes it easier for users (and reduces the temptation to flip the
cotton swab around and use the end you were just holding). We thought we would
try the Fisher Sci version of these (they were half the cost) and unfortunately
they have about ¼ the amount of cotton winding as the Puritan Branded ones. You
don’t need the double end but the Fisher brand ones barely have anything
on them. Rather useless.
3) Sparkle Glass cleaner. Ammonia free is important, basically any
ammonia free cleaner (I would avoid the vinegar enhanced ones). Or at least
the importance was impressed on me that it could potentially remove the coating
on the objective. I’m less concerned about the cement holding the
objective lens in than I am of removing any coating on the objective glass
itself. You can order this stuff direct (http://www.glasscleaner.com/ ) they have a Microscope lens cleaner but it just seems to be an
expensive dye free version of the regular glass cleaner, but there are
choices. I personally like having the purple stuff because it is a visual cue that
you are using something different and specific. Having a clear solution I
would be more concerned with someone using it on the water immersion objective
or using water to clean the oil (words on a label aren’t always read).
Procedure:
Take one sheet of lens tissue out. Hold
it flat by a corner. Dip the Cotton applicator into the bottle of Sparkle. Then
place (the clean side towards the objective) a section of the lens tissue close
to your fingers holding the tissue on the objective. Then with the damp/wet
(not dripping) applicator apply a slight amount of force and drag the clean
side of the tissue across the objective. Repeat until there is no more oil on
the objective. You can tell it is clean by turning the paper over and looking
for the shiny tell tale streak of oil. When the last few damp passes dry the
tissue shouldn’t be shiny. Occasionally it takes more than one pass to clean.
Again, this is for inverted microscopes.
Dry Objectives that get oil on them? Sometimes
it is easy. But then I just go right to the cotton applicators and Sparkle, very
gently cleaning and always getting new applicator. Often I will resort to
plain old Q-tip swabs for cleaning dry objectives. Holding them in the middle
get one end wet, ever so lightly swirl the sparkle over it, flip it around and
dry, and repeat until the surface is completely clean under magnified
inspection. If something is very stubborn but moving around (hard stuff like
mounting medium I have fortunately not encountered on objectives here) I will
soak just the very tip of the objective in a bit of full strength sparkle for a
period of time (10-15 minutes or more), then clean with the swabs, and inspect
and repeat until it is nice and clean. So far that method has served me quite
well in the ~14-15 years I’ve been cleaning oily dry objectives.
Geoff Williams
Leduc Bioimaging Facility Manager
From:
Sent: Tuesday, March 31, 2009 4:04
AM
To:
[hidden email]
Subject: Re: Cleaning lens.
Dear All,
I found this article on the
www.olympus.co.uk/microscopy/images/illum_cleaning.pdf
I've used a cotton swab with methanol without any problems, yet.... Based on
this discussion I might move to an ether/MeOH mixture!
Cheers
Neil
Date: Mon, 30 Mar 2009 11:39:36
-0400
From: [hidden email]
Subject: Re: Cleaning lens.
To: [hidden email]
Dear all,
While working for a Leica Microsystems dealer the local field service engineer
(factor trained) used a sequence of ethanol and heptane to clean truly dirty
lenses. For standard cleaning a lens wipe and Sparkle was his
recommendation. But for dried oil or the like he would graduate to cotton
swabs and either ethanol then heptane or a 50:50 mix of the two.
Chris
Chris Tully
Microscopy and Image Analysis Expert
[hidden email]
240-888-1021
http://www.linkedin.com/in/christully
On Mon, Mar 30, 2009 at 10:12 AM, Ian Montgomery <[hidden email]>
wrote:
Keith,
Methylated spirit that’s what he said, although I still prefer and use
ether when necessary.
Ian.
Dr. Ian Montgomery,
Histotechnology,
I.B.L.S. Support Unit,
G12 8QQ.
From:
Sent: 30 March 2009 14:12
To: [hidden email]
Subject: Re: Cleaning
lens.
Are you sure the Zeiss
Engineer didn’t say ‘petroleum spirit’? Methylated spirit is
mainly ethanol, and so best avoided - the Axiovert 100 manual says repeated use
of 70% ethanol will damage the objectives [but you can use it if you want].
Generally the faster the solvent evaporation from the lens/cement area the
better, hence the suggestion of the solvent [pure] diethyl ether by many [and
that’s what I use].
‘Zeiss cleaning
mixture L’, which the engineer’s now use since diethyl ether has
been withdrawn from their kit, is 90% by volume ‘benzoline’
[petroleum ether sometimes called medical alcohol] and 10%
‘isopropanol’ [2-proponal, dimethyl carbinol, 2-hydroxyproparne].
The bottle says ‘Clean the optics by moving in circles, slight pressure
should be exerted on optics during cleaning’. Petroleum ether or spirit
isn’t the same as the diethyl ether solvent/anaesthetic often used to
clean objectives, but apparently it does the job for Zeiss optics.
Keith
---------------------------------------------------------------------------
Dr Keith J. Morris,
Molecular Cytogenetics and Microscopy Core,
Laboratory 00/069 and 00/070,
The Wellcome Trust Centre for Human Genetics,
Telephone: +44 (0)1865 287568
Email: [hidden email]
Web-pages: http://www.well.ox.ac.uk/cytogenetics/
From:
Sent: 30 March 2009 12:28
To: [hidden email]
Subject: Cleaning lens.
In one of our teaching labs many years ago a student complained they were
having a problem with the x100 OI objective and sure enough the image was
lousy. I cleaned the objective and slide then re-applied a spot of oil and still
the image was lousy. I then asked the student how exactly they had set up the
microscope. Shock horror, my world collapsed. They had unscrewed the objective,
filled it with oil, screwed it back on then put a drop on the slide. After
weeks of trying to clean the objective it went into the trash as beyond
economic repair.
Cleaning objectives, I use the fluid recommended by the local Zeiss engineer,
90% methylated spirit and 10% isopropanol.
Ian.
Dr.
Ian Montgomery,
Histotechnology,
I.B.L.S.
Support Unit,
G12
8QQ.
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