Varied resolution in the same gel - (Oct/15/2010 )
Hi all.
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.
Thanks 
Do you use different comb types for both parts of the gel? Because the upper pockets look thinner and longer compared to the lower ones. If possible take the type of comb with thinner teeth for both parts of the gel. Thinner pockets permit less sample diffusion resulting in sharper bands after elecrophoresis.
ElHo on Fri Oct 15 09:51:04 2010 said:
Do you use different comb types for both parts of the gel? Because the upper pockets look thinner and longer compared to the lower ones. If possible take the type of comb with thinner teeth for both parts of the gel. Thinner pockets permit less sample diffusion resulting in sharper bands after elecrophoresis.
Yes, we use different comb types. But they have always given good bands, until i recently made fresh TBE buffer (checked online for recipe and made no mistakes).