How stable is MAO in vitro?

[Esa-Pekka P{lvim{ki]

I am contemplating using monoamine oxidase (MAO) to get rid of endogenous
serotonin in brain sections. Extensive preincubation is out because I don't
want to dissociate certain other substances from the sections. I'm thinking
off adding MAO directly in the incubation buffer, hoping that it will 
penetrate into the tissue and cause degradation of monoamines in situ.
If anyone has any insight regarding the stability of MAO in RT, or +37C, 
please e-mail or post.

Cheers, 
ep