I am facing this problem when I run a large gel. The sample loaded in the upper part of the gel are fine and have a good resolution, while those loaded in the lower lanes resolve badly. All samples come from the same PCR setup run at one time.
I have run the left over PCR products (of the bad resolution ones) on a fresh (smaller)gel and the resolution is good.
Help needed. I am bored of running the same samples twice.
Edited by gt_ameya, 14 October 2010 - 10:20 PM.