SDS-PAGE frowning :( - (Sep/22/2006 )

I have ran several gels for several years and have bought a new Protean 3 appartus from Bio-Rad switching over from the old model. I did not have any problems until I ran 2 gels at once and one gel ran faster than the other and they are frowning badly.
I have measured the voltage from the leads and power supply and everything looks fine, so what's the deal?

tamtam

same gels, prepared together?

If you are using Bio-Rad gels, you have to be really careful when you cut the bottom strip off of them and make sure it is straight and completely removed from the black line down. I had several gels that ran sideways or very slow because I didn't cut them correctly.

if you're running 2 at once at the same voltage you normally do, odds are that the power (watts) must increase. as that happens, the temperature of your buffer and gels will increase, causing the "frown."

you can either do one of 2 things:

- decrease your voltage

- run your gel in a cold room on ice. be sure to have this on a stir plate to make sure your temperature stays constant througout the apparatus.

funny you should mention voltage, which is exactly what i did; gels normally run at 100V to stack then 150V to run and I turned it down to 75 and that was the worse frowning I had ever seen.
i have ordered from pierce to check those since you don't have to cut the bottom.
thanks again!