Fixing a gel - meaning? - (Oct/14/2001 )

Does anyone know the details behind why one would "fix" a gel and what this process does to the proteins in the gel. Im referring to the process of incubating an SDS-PAGE gel in 7 or 8 % acetic acid or isopropanol after running the gel in preparation for Coomasie staining for example. Does the acetic acid somehow "fix" the proteins into the gel so that they do not diffuse away?

thanks

- ryan

i often questioned this when i was in grad. school. i firmly believe it was somewhat of a superstition. i have fixed and not-fixed gels and then dried down and developed and i really never detected a difference. I think it really is based on the training of your PI -who in turns passes it down to us!<p>in theory though, i believe it is meant to make the bands appear more concise and not so diffused.