[Histonet] Postfixation of frozen brain tissue

[Robert J. Schloesser]

Hi All, 

We have to do IHC on fresh frozen brain samples perfused only with saline. I
am only used to cutting and IHC on PFA fixed brains. 
Therefore I have many questions on how to treat fresh frozen samples. 

Postfixation on slides: PFA or Acetone/Ethanol? 
Is there a reliable way to postfix whole blocks?
Is there a way to postfix 30-200µm thick slides without mounting them on
slide (to do free floating staingin)? 

Any kind of input, protocols or tips&tricks and do`s and don`t are highly
appreciated. 

Thank you very much

Robert