ROS in cells

Dear Flowers,
I have a question about analysing ROS in cells. We have good experience
measuring ROS using DCFH in cell lines. Unfortunately, we have to repeat 
this assay in cells from a knock-out model which express GFP as a marker.
As DCFH and GFP are influencing each other, we are on the search for
a ROS marker with an excitation over 600 nm. We searched in the  
Molecular Probes catalogue, but there is no product which have a broad
spectrum of radicals to be measured like DCFH with a red excitation.

Do anybody know a substance to measure ROS (like DCFH) with such a
red excitation?

We hope that somebody can help us.

With regards

 Andreas





Doz. Dr. Andreas Simm
Department of Cardio-Thoracic Surgery
Martin-Luther University of Halle-Wittenberg
Ernst-Grube-Str. 40
D-06120 Halle / Germany
Tel:  +49 - (0) 345 557 2647
FAX:+49 - (0) 345 557 7070