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

[Nicholas David Evans]

Dear all,
 
I am doing some experiments where mouse skin tissue is harvested for
immuno and in situ staining at 2, 4, 6 and 8 days following a treatment.
The usual protocol used in our lab (for other tissues, usually bone) is to
fix overnight in 4% PFA before dehydration and paraffin embedding. As I
value my weekends, I would obviously prefer to do the dehydration (which
we do in ethanol series, an hour in each of 30, 50, 70, 90, 95, 100%
ethanol = 6 hours, before overnight in 100%) and embedding of all samples
on the same day. 
 
I understand that storage in PFA for longer than 24 hrs may adversely
affect my tissues. Is it possible to store for longer in a lower
concentration of PFA, or in another buffer until I am ready to dehydrate
and embed? In short, I would appreciate if anyone could suggest a way to
plan this experiment in the most efficient way. 
 
With thanks and best wishes
Nick Evans
 
Dept Surgery
Stanford University