Hi Lynn, 
We do tons of Rna section in situ and I have upon occasion left samples 
in 4% pFA for 2 days and had no problems detecting signal
Carolyn Pressman
MD Anderson Cancer CEnter
Houston Texas

On Thu, 8 Jul 1999, Lynn Gardner wrote:

> Hey histonetters,
> 
> Have a question about RNASE insitu we have some aorta and pulmonary artery
> tissue fixing in 4% paraformaldehyde for RNA insitu. If we have to leave
> the tissue in the paraformaldehyde over the weekend will this be a problem
> for the staining? We have left it up to 24 hours but not any longer than
> that. 
> 
> Thanks for the help.
> Lynn Gardner
> 
> 
>