Fluorogenic Beta-gal substrates

[William Meikrantz]

I would like to hear from anyone who's had experience using fluorogenic 
beta galactosidase substrates for detection of transient lacZ expression 
in eukaryotic cells.  I've been using (or trying to use) resorufin 
beta-D-galactopyranoside but am having problems with red autofluorescence 
(!?) and spontaneous hydrolysis of the substrate--all my cells keep 
coming out red, when I'm expecting transfection rates of around 10-40%.  
Thanks for any help!

--
Bill Meikrantz
meikrant at husc.harvard.edu