Buffer in Gel - (Sep/17/2012 )

Hi guys,

How often do you change the buffer in your gel electrophoresis. I am talking about the buffer in the gel tray.
And how often should it be changed (recommended)?

i never reuse electrode buffer. others do but i feel that i get more consistent results by changing it.

I use fresh TAE every time I run a gel. For some reason I get a heavy smear on top of my gel if I run with a used buffer. But as mdfenko said, many people reuse the buffer.

If I need the gel photo for my thesis (or publication) I use fresh buffer.

If I'm just running a quick gel to check a PCR or something, I'd reuse the buffer in the tank for a second or third time.

I may run two gels if I am doing both, after loading fresh buffer. But I do not trust the buffer left over in a gel box others have used. I even wash the gel box out after I'm done (probably the only time it ever gets washed).

After reading your thoughts, i have decided that i won't use the buffer more than twice.
Thanks !!

I've seen using 0,5x TBE buffer repeatedly each day for a week. Even if not used every day, changed after week. All were short runs, about an hour.
If there was or is going to be a longer run, use fresh buffer. You can tell the condition of your buffer by the amount of heat the gel produces, if it goes warm it's not very good. But it still may not affect the results much.
I don't run elfo regulary so I reuse only when I do a set of electrophoresis, I didn't manage to force people to label the tanks with date the buffer was used last time and number of times it was used, so when I'm doing elfo after some tome and come to the tank with buffer I rather change it, because it may be off.

I wouldn't reuse TAE, it's bad as it is already.