Apparently ethanol [and acetone] is a poor choice for cleaning oil
objectives and does damage the lens cement after very frequent use
[particularly with older microscopes]. The Zeiss engineer's used to use high
grade Ether [which I still do if it's essential to clean]. But health and
safety [carrying it about on the bus] meant they switched - Zeiss will sell
a bottle of what they now use now, some sort of industrial petroleum spirit
solvent [forgotten what it is, the engineer did tell me].

http://www.zeiss.com/C1256F8500454979/0/F9B766E00E70F4C4C1256F8D0054FFF8/$fi
le/thecleanmicroscope.pdf

However "The issue of the use of solvents is complicated, and is confused by
contradictory recommendations in the scientific literature, as well as by
differences in manufacturers' technical publications." 

http://micro.magnet.fsu.edu/primer/anatomy/cleaning.html

Older immersion oil can get more viscous [as well as probably more acidic]
with storage after opening and so becomes more difficult to remove, so
replace the bottle if it's not used for years. The advise I found was don't
rub hard when cleaning, but soak for a few seconds and then draw off the
solvent/solution.

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/
 

-----Original Message-----
From: Confocal Microscopy List [mailto:[log in to unmask]] On
Behalf Of Mike Tighe
Sent: 27 March 2009 19:41
To: [log in to unmask]
Subject: Cleaning lenses

Since you are all on this subject. What would you recommend cleaning
objectives with? I have always used absolute ETOH. Is there any reason this
would harm the objectives? Is there something better?