Hi Jennifer -
For EM purposes its not a good idea to store in fixative for any lengths of 
time. GA keeps on cross-linking which affects structure at very high powers.
How long is an endless question; many procedures have somewhat arbitrary timing 
schedules suggested, these can be modified but taken to extreme the result will 
be poor. Storage in buffer is better than in GA, but slowly some of the lipids 
will be lost.
Don't store in fixative. Store in buffer or low alcohol for not much over a 
week. Then process and embed and cure.
Cheers
Jim Darley

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On Tuesday, July 13, 1999 1:09 AM, Berger, Jennifer [SMTP:jberger@lrri.org] 
wrote:
> We are going to be embedding rat lung tissue in GMA . How long can you store
> the tissue in a fixative of paraformaldehyde 1% gluteraldehyde in a
> phosphate buffer?
> Thanks
> Jennifer
>
> Jennifer Berger
> Lovelace Respiratory Research Institute
> Albuquerque, NM
> jberger@lrri.org
>