| | Re: Fixing Cells with GFP Expression
we routinely fix cells with methanol at -20 degrees for 15 minutes. This always gives a good GFP expression. Usually I don't even use an antibody however, a post-doc in my lab is amazed because in his previous lab the methanol killed the GFP.
I'm not sure if it's the quality (we use 99.9% pure) of methanol, the time allowed to fix or the GFP itself (there are now many different mutant forms). I also maintain GFP when fixing with 3.7% paraformaldehyde (PFA) for 20 mins at room temp. Really, the only time I've had trouble maintaining GFP is when trying to co-stain for BrdU but I've got that one worked out now as well.