The effective probing depth is a function of many factors.  The objective as
a combination of N.A. and magnification, tissue density, R.I. and the probe
of interest all play a part.   You should take care to choose an objective
and probe combination that would allow for the gathering of light from the
deepest portions of the tissue.  This means the lowest N.A. you can get away
with, the lowest magnification that will allow you to clearly discriminate
your objects of interest, and the dye of choice should be the least
energetic variety possible, meaning orange or red.  The less energetic the
excitation light has to be, the more likely it is to penetrate the tissue.
This is a give and take process.  By going deeper, you will have to
sacrifice lateral resolution to some extent.
With more specific information, I'm sure the listmembers could provide less
general suggestions.
best of luck
        -Ramin

-----Original Message-----
From: Sven Terclavers [mailto:[log in to unmask]]
Sent: Monday, December 17, 2001 8:15 AM
To: [log in to unmask]
Subject: Deep scan


Dear colleagues,

Is it possible to make an optical z-scan of more than 200 micrometer thick
(for 3D-rendering) in 0,5 to 5,0 mm thick tissue with a Zeiss LSM510
HeNe/Argon confocal lasermicroscope?  I only managed to get a sharp 3D-image
of 150 to 200 micrometers thick as a maximum.  In other words, how deep
should I be able to scan in tissue with a confocal microscope (without loss
of sharpness)?
Thanks,

Sven Terclavers
Research Assistent
Center for Molecular and Vascular Biology
V.I.B. O/N
Herestraat 49
3000 Leuven
Belgium