Shadow in agarose gel - (Jan/04/2007 )
Hi!
I´ve got a big white shadow covering 3/4 of my gel 
, and the DNA bands were weak and diffuse, but the marker was fine. Can someone give me any advice? I used a fresh gel and a fresh 1x TBE.
Thanks! 
can you post the gel picture? what was the protocol you followed? 
EtBr problem?
running buffer(try fresh prepared), or the camera maybe???
sandragen
This sounds like what happens when EtBr is added to the gel, and no EtBr is added to the running buffer. EtBr migrates the opposite direction than DNA, and the EtBr at the positive terminal will migrate, leaving an unstained regions at the positive end. Add EtBr to the running buffer at the positive end to eliminate this problem, or post-stain the gel.
once it happened to me and the problem was that the gel cracked and DNA leaked all over the gel. or that was what i thought it was what 1% of gel you are using? put the gel at 4C for some time before running it.
Yes, that should have been the problem..
Thanks!!
what 1% of gel you are using? put the gel at 4C for some time before running it.I´m using 1% agarose in TBE. I will try putting it at 4°C, thanks for the suggestion
what 1% of gel you are using? put the gel at 4C for some time before running it.I´m using 1% agarose in TBE. I will try putting it at 4°C, thanks for the suggestion
actually in my case it was low melting temperature agarose. but anyway i keep the ordinary get at RT for 2 min and then put at 4C for 15 min to avoid any trouble.