I've tissue samples originally fixed for FISH, which i would very much like to use for transmmision electron microscopy. my problem is, does my fixation fit TEM?
i had fixed for 20 hours in 4% formaldehyde at 4 degrees, then washed away the formaldehyde with PBS and kept the samples at 1:1 ethanol:PBS , at -20 degrees, for the past 4 months.
I've been told, for TEM, that gluteraldehyde fixation is best and that samples should be kept at 4 degrees in glutaraldehyde buffer.
will my samples be usable anyway? if not, is there a way to "fix" this problem? (short of getting fresh samples, which i wont be able to do till summer...)