Paraformaldehyde fixation! - in IHC (Aug/06/2009 )

Just want to know how long can we store 4% PFA fixeds cells before taking up for further immune-staining steps!

Depends how you are storing them, if in the fridge under PBS or other buffer, a week or two at the most, so long as they stay sterile. If frozen, as long as you like. It is however, better to freeze the slides/coverslips after staining.