[Histonet] Storage of tissues in PFA before dehydration and embedding

[Emily Sours]

We fix our embryos overnight in 4% para for in situ's--the long crosslinking
helps fix the RNA better.  For some immuno's though, too much fixing is
definitely bad.  Why not store in PBS until you're ready to dehydrate?
Oh, (a note of caution?), we don't use para fixation for paraffin embedding,
though--we use a much harsher fix, like modified Carnoy's or Serra's fix.
When we fix with those, we store the embryos in 70% over the weekend (which
is the next step after fixing for two to four hours--washing in 70% EtOH).
These embryos can only be used with certain antibodies and very strong RNA
probes.
Btw, our tissue is young chick embryos--E2 to E8.

Emily

"Canned food is dead food....here kids can't study.  They're going blind.
 Mothers are out in pants showing themselves off when they ought to be at
home cooking fresh vegetables."
--Charles Atlas, Saga magazine interview, 1964