Search the CONFOCAL archive at
http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal

Hi Ken,
What are the gaskets made of? Are they simple "O" rings or a special
shape. It would seem that a material change is in order. Viton (a
fluorocarbon rubber) is resistant to just about every oil and solvent in
common use and standard size "O" rings are available in this material.
Sheet, tube and even heatshrink tube are also available. Zeiss may have
a good reason for not using Viton (the only disadvantage I know is that
it produces hydrofluoric acid as a decomposition product when burned,
not a problem for this application), perhaps a rep could comment.

Robert.

-----Original Message-----
From: Kenneth A. Orndorff [mailto:[log in to unmask]]
Sent: 29 April 2003 19:18
To: [log in to unmask]
Subject: Re: Objective gasket failure


Search the CONFOCAL archive at
http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal

Confocal BB,
        Thanks everyone for the tips on cleaning.  I would like to say
that we do indeed use these good cleaning habits and we try to take
excellent care of these very expensive elements of the system. It is
really the more serious issue of what I believe is objective failure at
the gasket that I wanted to address.
        Tom Gore is reporting exactly the type of problem that I think
we should expect to be able to avoid with reasonable care and treatment
of our objectives.  I am especially concerned about objective failure
because our core facility has just purchased a new inverted confocal
system that will  emphasize live cell work.  Therefore, the inverted
objective will be far more easily covered in oil. I  expect that the
higher  37C temp also  places a much greater demand on the seals of the
objectives.  We have a water immersion objective for the long term
studies of live cells.  But other core facility users with fixed samples
will also want to use the system when it is warmed, so the issue of oil
running down the objective will still occur.
        Are microscopists to consider $5000.00 +  objectives as
disposable items? I would like to think not.  This is my first
experience with a gasket failure in nearly 25 years of working with
microscopes. Thus, my first response was that something funny was going
on.  So I am just checking with  with everyone to see if similar events
are happening out there.
        I  wonder if it might  be possible for microscope companies to
recertify the objectives for a much reduced cost than required when a
total failure occurs.  Possibly providing a loaner?  I can dream. :-)
Is it possible to remove aging but intact sealant and apply a new
coating at a much reduced cost and much more quickly? Is it possible to
avoid designs that have readily exposed sealing gaskets?   Any thoughts
that you have would be of interest to me.  Thanks again to all.


Ken

Ken Orndorff
Supervisor-Imaging
H.C. Englert Cell Analysis Lab
Dartmouth College/DMS/NCCC
Borwell Building Room 338 West
One Medical Center Drive
Lebanon, NH  03756

Phone 603-650-7661
FAX    603-650-6130
http://www.dartmouth.edu/~celllab

Any opinions expressed in this email are those of the individual and not
necessarily Genetix Ltd (Genetix) or any company associated with it.
This email and any files transmitted with it are confidential and solely
for the use of the intended recipient. If you are not the intended
recipient or the person responsible for delivering to the intended
recipient, be advised that you have received this email in error and
that any use is strictly prohibited. If you have received this email in
error please notify Genetix by telephone on +44 (0)1425 624600.

The unauthorised use, disclosure, copying or alteration of this message
is strictly forbidden. This mail and any attachments have been scanned
for viruses prior to leaving the Genetix network. Genetix will not be
liable for direct, special, indirect or consequential damages as a
result of any virus being passed on, or arising from alteration of the
contents of this message by a third party.