Search the CONFOCAL archive at
http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal
Hi Bob,
Unfortunately, z-resolution is a function of many variables. One of
these is the precision of the z drive. Is there any chance this may
have been relevant?
You don't say in your posting how, exactly you come up with the z-res
number (FWHM?), but this can be "improved" by setting the black level
too low (below zero).
Is the BFP filled in both cases? (Hook up Koehler Illumination with
an oil condenser and look and the shape of the laser beam coming out
of the condenser.)
Whenever you get a result better than theory,it is a strong
indication that you may have missed something.
Cheers,
Jim P.
>Search the CONFOCAL archive at
>http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal
>
>Confocal question
>All microscope objectives have a magnification and a numerical aperture
>( NA) -- However not all similar lenses of the same magnification and
>same NA from the same manufacturer are equivalent. The resolving system
>of a confocal microscope can be checked using a single reflecting mirror
>or a bead as has previously been described in Zucker, R.M. Price OT
>Evaluation of confocal system performance-- Cytometry B44:273-294 2001
>.(PDF files available)
>One Plan Apo 100x lens yielded a value of 410nm while on the same
>confocal system another Plan APO 100x lens yielded a value of 190nm was
>achieved. Usually most 100x plan Apo lenses will yield under 350nm. The
>mirror test was done in a similar manner. I am having difficulty
>explaining this data as the value is below the theoretical limit of 230
>nm. The tests were done with the assistance of a very qualified
>technician and they were done correctly.
>
>Can a 100x Plan Apo lens have a numerical aperture greater than 1.40. If
>not how do you explain this data. ??
>Bob
>
>Robert M. Zucker, PhD
>U.S. Environmental Protection Agency
>Office of Research and Development
>National Health and Environmental Effects Research Laboratory
>Reproductive Toxicology Division, MD 72
>Research Triangle Park, North Carolina, 27711
>Tel: 919-541-1585; fax 919-541-4017
>e-mail: [log in to unmask]
--
****************************************
Prof. James B. Pawley, Ph. 608-263-3147
Room 223, Zoology Research Building, FAX 608-265-5315
1117 Johnson Ave., Madison, WI, 53706 [log in to unmask]
"A scientist is not one who can answer questions but one who can
question answers." Theodore Schick Jr., Skeptical Enquirer, 21-2:39
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