Hi,
I've tried to follow most of this thread but may have missed some. Seems
that most of the discussion is related to solvents to remove (primarily)
oil. I haven't seem much mention of the aqueous-based cleaners. We have
only used these type of cleaners for decades with no problems. Our
standard procedure for dry lenses is to use a dry cotton swab to mop up
the excess oil in the groove and the surrounding parts that are NOT the
optical surface; then clean those same areas with a swab just moistened
with a single drop of lens cleaner (Kodak lens cleaner, Sparkle glass
cleaner (was recommended by service personnel of two major microscope
companies) or others; Zeiss supplied an aqueous lens cleaner and we
found a commercial product that is reputed to be the same material -
UltraClarity from FilmTools). I think some of these contain a bit of
isopropanol.
Finally, with a cotton swab just moistened and a very light touch, start
at the center of the lens and while spinning the swab between the
fingers also spiral the swab from the center to perimeter; this step may
need to be repeated. There should never be enough lens cleaner that it
sits on the lens - you should see the evaporating film receding
immediately if the cotton swab was just moistened.
In our multiuser facility where we have a range of users from novice to
seasoned professionals and undergrads to advanced postgrads and
professors (note the separation of the categories - they don't
necessarily line up) and we regularly find oil on the dry objectives and
perform this cleaning routine and the lenses do not appear to have
suffered from this method. The use of the objective to crush slides is
another matter; we have deep scoring on the face of the chromed-brass
barrel of a couple of objectives but (amazingly) no damage to the
optical surface which is slightly recessed and concave on the 20x and
40x - the long ones most likely to get oiled or be used for slide
crushers.....
I have always taken the view that oil lenses are designed to be in oil
(and are designed for that) and we just have people use a small square
of Lensx-90 to gently wipe the excess until the tissue "appears" dry -
obviously there will still be a film of oil but the lenses have not
failed in any respect from over 15yr of this protocol. Our microscopes
are used daily and frequently. For the record we use Cargille "DF" oil,
or the Zeiss 518F oil on our Axiovert200.
Once in a while - for mystery materials that range from mounting cement
to nail polish, etc. - we do use xylene sparingly as described for the
aqueous cleaner; first clean up the bulk of the mess away from the
optical surface and always use a just-moistened swab; again the cleaner
should not remain sitting on the lens.
I'm not reporting this as a "you should do it this way" statement; I
just wanted to add to the knowledge base of possible lens care and lens
survivability.
Dale
> ------------------------------------------------------------------------
> *From:* Confocal Microscopy List
> [mailto:[log in to unmask]] *On Behalf Of *Guy Cox
> *Sent:* 01 April 2009 11:00
> *To:* [log in to unmask]
> *Subject:* Re: Cleaning lens.
>
> When I first learnt about microscopes (a very long time ago) I was
> taught that while dry objectives often had their front element
> mounted with some adhesive, oil immersion objectives didn't - the
> element was held by a screw ring. Hence it was safe to clean them
> with solvent - we usually used xylene because that was handy - it
> was also used in mounting specimens (with canada balsam). Of course
> this didn't offer any solution to the clumsy clot who gets oil on
> the x40. But that wasn't actually quite so common then because oil
> immersion lenses were longer - ie not parfocal - so if someone swung
> the turret round the dry lenses would clear the oil. On the other
> hand this didn't make using oil lenses too easy - and they didn't
> have spring noses then either.
>
> Nowadays I'd have thought that if any adhesive is used it would be
> epoxy which is pretty much immune to solvents.
>
>
> Guy
>
>
> Optical Imaging Techniques in Cell Biology
> by Guy Cox CRC Press / Taylor & Francis
> http://www.guycox.com/optical.htm
> ______________________________________________
> Associate Professor Guy Cox, MA, DPhil(Oxon)
> Electron Microscope Unit, Madsen Building F09,
> University of Sydney, NSW 2006
> ______________________________________________
> Phone +61 2 9351 3176 Fax +61 2 9351 7682
> Mobile 0413 281 861
> ______________________________________________
> http://www.guycox.net <http://www.guycox.net/>
>
>
>
> ------------------------------------------------------------------------
> *From:* Confocal Microscopy List
> [mailto:[log in to unmask]] *On Behalf Of *Keith Morris
> *Sent:* Wednesday, 1 April 2009 6:47 PM
> *To:* [log in to unmask]
> *Subject:* FW: Cleaning lens.
>
> I think Zeiss’s comment that repeated use of ethanol will damage
> Zeiss’s lens cement was just that – use it a few times a day and the
> Zeiss objective will probably fail in 6 months or so [and this might
> be the case for many solvents, ethanol is simply one more readily at
> hand*]. Use ethanol every month or so and chances are the objective
> will last a lot longer [and fail for another reason]. Use ethanol on
> a very elderly microscope where the lenses are mounted in say gum
> resin though and you will destroy the objective pretty much
> instantly [or at least get a nasty smear of gum resin all over the
> clear bit] - hence some people’s historical aversion is justified. I
> did mention to a Zeiss rep why did he just use 70% ethanol on our
> new 100x zillion NA TIRF objective when Zeiss say that repeated use
> will damage the objective, he said, well repeated use will damage
> the objective, but once or twice won’t matter [and then I thought
> ‘well I suppose it’s not actually his £8,000 objective’]. Other
> manufacturer’s actually recommend ethanol, e.g. Olympus. However
> immersion oil doesn’t dissolve in ethanol that well, hence another
> reason for the recommended use of other solvents, e.g. Petroleum
> ether - see
> http://instrument-support.nikonusa.com/app/answers/detail/a_id/10379
>
> *from the micro/primer site: "In the past, solvents have been
> routinely employed for nearly any cleaning task in microscopy, and
> particularly for removal of immersion oil. Potential problems
> associated with solvent cleaning are sufficiently serious that the
> best current approach in cleaning the microscope is to use solvents
> only when absolutely necessary, essentially as a last resort rather
> than a first step. The issue of the use of solvents is further
> complicated and confused by contradictory recommendations in the
> scientific literature, as well as by differences in manufacturers'
> technical publications. Although alcohol and xylene are widely
> recommended as lens cleaning solvents, they are also named as being
> harmful to both the mechanical and optical components of many
> microscopes. Because of the variation in solvent recommendations,
> and the likelihood that some of the materials used in the instrument
> components are not known to the user, it is prudent to restrict use
> of any solvent to an absolute minimum.”
>
> i.e. have a look at:
> http://micro.magnet.fsu.edu/primer/anatomy/cleaning.html
>
> Most of this discussion of solvents only applies to immersion oil
> objectives, where the oil isn’t miscible in water. Our inverted
> microscopes with all air objectives are rarely cleaned, otherwise
> it’s just a blow with a puffer. On microscopes where oil and air
> co-exist it’s often immersion oil contamination of the air objective
> that’s the problem, so it’s solvents again. In the days when only my
> group operated the microscopes, with all our oil immersion free
> upright microscopes the objectives almost never needed cleaning.
>
> For other spillages such as culture medium [inverted microscope
> again] some solvents will probably fix biological muck onto the
> lens, and there’s the salts content, so the use of water based
> cleaners has been suggested [e.g. even breathing on the lens and
> then lens tissue, using optical/glass cleaning solutions]. Water
> drying onto the lens is a disaster though. Some even recommend
> things like breaking polystyrene foam [to get a clean surface] and
> gently rubbing the [oil free] lens with that. Or there’s Sparkle -
> whatever that is, here in the UK it was a silicon based furniture
> polish [yuk] not a commercial window glass cleaner. That’s the
> problem with industrial cleaners, who knows what’s in them or
> whether the constituents have been modified – you could try it on an
> inconspicuous area of the objective lens first, I suppose.
> Presumably optical lens cleaners are glass friendly though, and many
> use glass cleaning products with no reported problems. All the links
> in the previous posts [below] give loads of ideas for cleaning
> objectives [when necessary].
>
>
>
> _http://www.zeiss.com/C1256F8500454979/0/F9B766E00E70F4C4C1256F8D0054FFF8/$file/thecleanmicroscope.pdf_
>
>
> http://books.google.com/books?id=Dhn2KispfdQC&pg=PA51&lpg=PA51&dq=petroleum+spirit+cleaning+objectives&source=bl&ots=JxlHfCVuF5&sig=NTJt3Ol66sgsB8gluF1eKpeXLCc&hl=en&ei=DfvRSdGpI5WrjAflkvjlBg&sa=X&oi=book_result&resnum=1&ct=result
> <http://books.google.com/books?id=Dhn2KispfdQC&pg=PA51&lpg=PA51&dq=petroleum+spirit+cleaning+objectives&source=bl&ots=JxlHfCVuF5&sig=NTJt3Ol66sgsB8gluF1eKpeXLCc&hl=en&ei=DfvRSdGpI5WrjAflkvjlBg&sa=X&oi=book_result&resnum=1&ct=result>
>
> http://www.microscopy-uk.org.uk/mag/indexmag.html?http://www.microscopy-uk.org.uk/mag/artfeb04/cdclean.html//
>
> /
> <http://www.olympus.co.uk/microscopy/images/illum_cleaning.pdf>www.*olympus.co.uk/microscopy/images/illum_*cleaning.pdf**
> <http://www.olympus.co.uk/microscopy/images/illum_cleaning.pdf>********/**/
> /http://www.olympusmicro.com/primer/techniques/fluorescence/troubleshoot.html**
>
> ** **
>
> **
> Keith**
>
> ** **
> ** **
>
> **---------------------------------------------------------------------------
> Dr Keith J. Morris,
> Molecular Cytogenetics and Microscopy Core,
> Laboratory 00/069 and 00/070,
> The Wellcome Trust Centre for Human Genetics,
> Roosevelt Drive,
> Oxford OX3 7BN,
> United Kingdom.
>
> Telephone: +44 (0)1865 287568
> Email: [log in to unmask]
> Web-pages: http://www.well.ox.ac.uk/cytogenetics/**
>
> ** **
> ** **
> **
> ------------------------------------------------------------------------
> **
> ** **
>
> ***From:* Confocal Microscopy List
> [mailto:[log in to unmask]] *On Behalf Of *Chris Tully
> *Sent:* 30 March 2009 16:40
> *To:* [log in to unmask]
> *Subject:* Re: Cleaning lens.**
>
> ** **
>
> ** **
>
> ** **
>
> **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
> [log in to unmask] <mailto:[log in to unmask]>
> 240-888-1021
> http://www.linkedin.com/in/christully**
>
> ** **
> ** **
>
> **On Mon, Mar 30, 2009 at 10:12 AM, Ian Montgomery
> <[log in to unmask] <mailto:[log in to unmask]>>
> 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,**
>
> ** **
>
> **Thomson Building,**
>
> ** **
>
> **University of Glasgow,**
>
> ** **
>
> **Glasgow,**
>
> ** **
>
> **G12 8QQ.**
>
> ** **
> ** **
> **
> ------------------------------------------------------------------------
> **
> ** **
>
> ***From:* Confocal Microscopy List
> [mailto:[log in to unmask]
> <mailto:[log in to unmask]>] *On Behalf Of *Keith Morris
> *Sent:* 30 March 2009 14:12**
>
> ** **
> ** **
>
> **
> *To:* [log in to unmask]
> <mailto:[log in to unmask]>**
>
> ** **
>
> ***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,
> Roosevelt Drive,
> Oxford OX3 7BN,
> United Kingdom.
>
> Telephone: +44 (0)1865 287568
> Email: [log in to unmask] <mailto:[log in to unmask]>
> Web-pages: http://www.well.ox.ac.uk/cytogenetics/**
>
> ** **
> ** **
> **
> ------------------------------------------------------------------------
> **
> ** **
>
> ***From:* Confocal Microscopy List
> [mailto:[log in to unmask]
> <mailto:[log in to unmask]>] *On Behalf Of *Ian Montgomery
> *Sent:* 30 March 2009 12:28
> *To:* [log in to unmask]
> <mailto:[log in to unmask]>
> *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,**
>
> ** **
>
> **Thomson Building,**
>
> ** **
>
> **University of Glasgow,**
>
> ** **
>
> **Glasgow,**
>
> ** **
>
> **G12 8QQ.**
>
> ** **
>
> ** **
>
> ** **
>
> ** **
>
> **
> **
>
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