I think the issue of saponin permeabilisation was once discussed here,
but let me ask a question, again.

When you used saponin, do you always need to use the saponin/PBS for
each wash?  Can saponin interfare with hydogen peroxide, antibodies, DAB
substrate, or any fluorescence?
I know some people just use for the first 30 min. permeabilisation step
for TUNEL.  Are there any reason for that?

Thank you for your help in advance.
--
Masayuki Miyagishima, MD
University of Pittsburgh,
Department of Surgery