Hi Andreas, 

I didn't want to suggest that UV Raman is not used, but to point 
out that about the only practical reason to do so is resonant 
enhancement. The boost resonance gives to the Raman signal is so 
large, that it can override the otherwise serious complications. 
For biological samples NIR causes less damage but UV can greatly
improve sensitivity. 

Admittedly, there is one other reason people use UV excitation 
for Raman, and that is to study material surfaces, profiting 
from the very shallow penetration of the UV. 

Best Regards, 

Emmanuel


-----Original Message-----
From: Confocal Microscopy List
[mailto:[log in to unmask]]On Behalf Of Andreas Bruckbauer
Sent: Thursday, February 19, 2009 22:58
To: [log in to unmask]
Subject: Re: Raman dependence on exciter wavelength


I disagree with Emmanuel, UV Raman is an established technique, fluorescence
seems to be a problem above 300 nm, Semrock has some information on their
website. However you need special lasers, optics, spectrometer and detectors
which are more expensive and you might damage your sample easily. For
biological samples near IR is the wavelength of choice. 
In your sentence you would say "scattered" instead of "reflected" Raman
signal, it scatters can go in all directions.

Andreas