[Histonet] pepsin

[MKing]

An antibody vendor recommended pepsin pretreatment prior to primary 
antibody incubation of our free-floating 40 um formaldehyde-fixed rat 
brain frozen sections, but provided a protocol that only listed pepsin 
by weight.  Since enzyme activity ranges from 3 to 4500 units/mg in 
commercial sources, does anyone have a rough idea what kind of activity 
is sufficient without destroying the tissue (which is what happened with 
the first test).  Anybody find this approach worthwhile with similar tissue?
Thanks,
Mike King
UF Pharmacology & Therapeutics