Search the CONFOCAL archive at
http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal
Thank you, Gary.
After closer inspection, I can now confirm that it is dust that can be
wiped off with lens paper (I tried a small sample near the edge of the
disk) - compressed air does help with some of the larger particles, but
most of the smaller specks won't come off unless wiped.
I agree with your suggestion of using a cleanroom for maintenance.
Chrome masks are fairly robust, so I imagine that continuing to wipe
off with lens paper should be fine...however, I'll repost to the
listserv once I get a chance to fully clean off the disk to let folks
know how it goes <fingers crossed>.
I'm still a bit curious to know how many other users have the same
problem, but possibly aren't aware of it because they rarely look
through the disk when it isn't spinning. My confocal unit, while not
completely sealed off from the environment, is pretty well enclosed,
and my work environment isn't visibly dusty. So, If you use a Nipkow
disk it might be worth taking a look...
Best -Joe
On Jul 5, 2008, at 11:18 PM, Gary Laevsky wrote:
Search the CONFOCAL archive at
http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal
Not sure about the specific model of your disc, but could you possibly
hit it with a bellows? If dust, you could see some change in pattern
(as long as you keep the disc stopped/in the same position). If not
dust, the bellows is a relatively passive method of cleaning and
shouldn't exacerbate damage if it is chrome degrading. If it is dust,
I would suggest a clean room for the maintenance.
I also think it's great that you provided an image the way you did. A
great preliminary diagnostic.
Best,
Gary Laevsky, Ph.D.
Imaging Application Specialist
Andor Technology
discover new ways of seeing
[log in to unmask]
Cell (774) 291 - 9992
Office (860) 290 - 9211 x219
Fax (860) 290 - 9566
Web: www.andor.com
-----Original Message-----
From: Confocal Microscopy List [mailto:[log in to unmask]]
On Behalf Of Joseph Summers
Sent: Saturday, July 05, 2008 10:39 PM
To: [log in to unmask]
Subject: Re: Cleaning a Nipkow Disk
Search the CONFOCAL archive at
http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal
Hi Paul,
Thanks for the response.
I'll probably leave the disk alone, but I don't think think the specks
I see are due to holes in the chrome. As I bring a sample into focus
(while the disk is stopped), I see the pinholes get brighter as the
sample comes into the focal plane. For the specks, the brightness
doesn't change at all with focus. This leads me to believe that the
light I'm seeing is scattered from the surface of the disk, not light
from the sample through holes in the disk.
I also can't think of what would cause this type of damage if there are
in fact holes in the chrome. If it's damaged caused while spinning,
I'd expect the pattern to look more like long thin scratches. Another
possibility would be that something's corroding the surface...but such
a large amount of corrosion over a short amount of time seems very
unusual (I've seen this get worse since moving my setup from one lab to
another, over a period of just a couple of months). So, these factors
together make me think that it's some sort of dust...but I'd rather do
nothing than risk damaging the disk until I know for sure :)
Thanks again for the comments.
Best,
Joe
Quoting Maddox Paul <[log in to unmask]>:
Search the CONFOCAL archive at
http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal
Hi Joe,
Based on your picture, I would bet that, while dust may in fact be
building up on the disk, the "scattered light" you see is due to small
holes forming in the chrome masking. The reason I come to that
conclusion is because of the image you provided (very handy, thanks).
To make that type of image, you shine light through the stopped disk.
The pinholes are in focus nicely, if there were scattered light, it
would reveal itself as "blurring" of the pinholes and not as sharply in
focus features.
I could of course be wrong, but nonetheless, I would resist cleaning
this out of fear of increasing the size of those holes.
Best of luck,
Paul
Paul S. Maddox, PhD
Assistant Professor
Institute for Research in Immunology and Cancer
Dept of Pathology and Cell Biol, U. de Montreal
P.O. Box 6128, Station Centre-Ville
Montréal QC H3C 3J7
CANADA
Courier:
2900, boulevard Édouard-Montpetit
Pavillon Marcelle-Coutu, Quai 20
Montreal QC H3T 1J4
CANADA
[log in to unmask]
Ph: 514-343-7894
Fax: 514-343-6843
-----Original Message-----
From: Confocal Microscopy List [mailto:[log in to unmask]]
On Behalf Of Joseph Summers
Sent: Saturday, July 05, 2008 7:40 PM
To: [log in to unmask]
Subject: Cleaning a Nipkow Disk
Search the CONFOCAL archive at
http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal
Hi Folks,
I've been using an old Technical Instruments K2-IND Nipkow disk
confocal and have been noticing some buildup of dust between the
pinholes on top of the chrome-plated glass disk. This dust is
scattering light and is clearly visible between the pinholes when the
disk isn't spinning. I've posted a pic here:
http://www.mtholyoke.edu/~jsummers/dust_pinholes.png
(*note: I'm fairly certain that this is scattered light from dust on
top of the disk, and not due to light transmitted through
damage/scratches in the chrome because 1) the brightness of the "dust"
doesn't change with focus, 2) I would expect scratches to look like
streaks, 3) I can see what appears to be dust on the disk with the
naked eye when opening up the K2-IND unit)
Though this isn't much of a problem now, I imagine the attainable
contrast of the scope will degrade over time as more dust collects.
I'm not using the microscope in a cleanroom environment, so I suppose
this type of thing would be expected. However, I'm curious to know if
anyone has any suggestions for cleaning the disk. I've tried using an
air-gun, but this doesn't really help. I'm tempted to use some lens
cleaning paper and isopropyl alcohol, but since the problem isn't bad
yet (and the scope isn't all that cheap), I wanted to see if there was
any expert advice out there.
I'd appreciate any input.
Thanks and best,
Joe
------------------------------------
Postdoc, Physics Dept.
Optoelectronics Group
Mt. Holyoke College
ph: (413) 538-2263
http://www.mtholyoke.edu/~jsummers/
----------------------------------------------------------------
This message was sent using IMP, the Internet Messaging Program.
----------------------------------------------------------------
This message was sent using IMP, the Internet Messaging Program.
|
