WARNING: Posting from a Commercial Domain!
     Despite protestations to the contrary it is quite possible to efficiently
image Texas Red with a 625nm long pass filter.  I used a 630 [Hanzel et al EMBO
J., 1991, 10:10:9:2363-2373] to achieve <2% crosstalk of the Texas Red signal in
the Fluorescein Channel (540DF40) and this was with an Argon Ion Laser
(488/514).  Our users routinely image Texas Red and Propidium Iodide with
barrier filters of 600 to 625EFLP depending on the strength of the red signal
and requirements for spectra separation.
david hanzel
Molecular Dynamics
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http://www.mdyn.com
 
 
______________________________ Reply Separator _________________________________
Subject: 625nm long pass for Biorad 600 A2 to reduce bleed
Author:  Confocal Microscopy List <[log in to unmask]> at Interlink
Date:    8/10/95 8:33 AM
 
 
Has anyone replaced the 600nm long pass filter in the A2 block with a
longer wavelength cutoff?  This would reduce the bleed of the red end
of the FITC emission through the red filter.  It seems as if a 625nm
cutoff would be appropriate and would not sacrtifice too much of the
red emission fro texas red etc.  Has anyone tried this?  How were the
results?  From whom was the filter purchased?  Omega Optical can
supply one on special order and said it should be polished and AR coated
for imaging applications.  Has anyone purchased a suitable part from another
company?
Thanks.
 
Milton Charlton
University of Toronto