Alison, One thing I found when running gels that caused this was if you had a
salt imbalence due to difference between the buffer anf the gel. We used to see
this when we would use the last of our 10x stock to make the gel, and then use
a fresh batch of 10x to make the running buffer. The gels were swelling because
of the imbalence. Check the pH of the buffer. Also be sure that you did not use
just water in the buffer chamber, or did not really under dilute the running
buffer. Hope this helps
