If I understand correctly, you are asking how long one can wait befor doing staining. It depends on the epitope of course - phospho epitopes degrade faster, but I've stained cells with Mabs targeting them after a week of sitting on the 4 degree fridge (for strong signal), the week ones probably degrade faster (but I used to do fix on Friday, staining on Monday - overnight primary one of course). For regular protein epitopes it can be even longer than a week (but I can't recall waiting longer than a week). Usually, if you didn't stain within a week it means you are not really interested enough in the answer :). Good luck!