dear folks

After the flurry of discussion on quenching endogenous peroxidase-like
activity, I tried one of the protocols.  It was the one using 3% peroxide
in PBS.  This one is also called for in the ONCOR Apotag Kit.  I don't
recommend following the instructions in this detail if you are looking at
apoptosis in rat brain.

My tissue is rat olfactory and VNO epithelium transplanted to rat brain.
With a five minute bath in the above peroxide solution, I had plenty of
DAB(+) cells in my secondary control (i.e. no primary).

With a five minute bath in 3% peroxide/absolute MetOH, the control slide
was clean.  I grant that, at the same primary dilution, the signal was
attenuated but still acceptable given the dramatic decrease in
background.  By the by, the background was not a generalized brown but
infact subpopulations of cells that showed DAB as well as any good
positive should.

Can someone explain the difference here?



John Carroll Dennis
Anatomy, Physiology, and Pharmacology
109 Greene Hall
Auburn University, AL  36849