Dear All:

Thanks for all of your various inputs.  However helpful they have been,
I am a silly, big-haired girl and need some more assistance.  First, I
think that I really must make clear what I am thinking about doing in
the experiment, although I do believe it is clear to you all.  The idea is
to focus a beam (cone if inevitable) of light as the STIMULUS for a
small region of a cell, or at least a single cell and then use the CLSM
to measure real-time responses (if any) in the illuminated cells.  Our
interest is in the UV range and although it would be the best of all
worlds to be completely monochromatic, a narrow (2-10 nm) would
suffice at least for pilot studies.  My hair requires that I ask of you all
to help me with the following:

1) What precisely do you mean when you say that the beam properties
    will be no longer as they began after a trip through the fiber optic?
    I hate to be obtuse but I need a more exact explanation (again due
    to the density of my hair)
2) What are the characteristics of these rumored UV-capable (fused silica
    fiber optics?  Johannes - you can just give me the references
3) Does the following sound practical/possible/adequate...

I was thinking of a light source of wide range (Xenon, etc) followed (in
the light path) by a set of interference and neutral density filters to select
wavelength and adjust intensity of the light.  Then this would be collected
with a suitable fiber optic (fused silica?) that would end in a light guide
which is tapered at the end - similar to a patch-pipette.  This is then held
by a micromanipulator and "focussed" onto the cell(s).  This is in use
with some investigators doing another thing with visible range light.

My Questions:

1) Can I use a conventional fiber optic in this system?
2) If not, what is required?
3) Can I do something to avoid the use of the micromanipulator via
     an actuated dual-shutter to rapidly switch from the stimulating "beam"
     to the excitation beam of the CLSM?  (This would of course be through
     the objective of the scope)

We'll have a Bar-B-Q after my Nobel Prize if you help me.

Susi