I'm repeating an experiment, and when I did the DNA electrophoresis, The ladder and bands migrated weirdly and I can't see most of the bands. I used a different pipette than the one I always use (this one is very descalibrated), reason why I added more EtBr than the amount I usually use (2 uL of 10 mg/mL EtBr for a 50 mL 2,5X agarose gel).
I blamed the TBE buffer (which it wasn't perfectly clean), I changed it, and did the gel again. Same problem. I would blame the PCR, but there's problems with the ladder migration. The funny thing is that the migration front dye, migrates just fine, is just the DNA.
There's still like "empty space" where the DNA should be (not orange)
So, the question is: can too much EtBr interfere with the DNA migration? (because it migrates in different direction than DNA)
Also, why the only bands I can see are the ones in the middle of the gel?
Edited by ccostoya, 25 September 2014 - 12:52 PM.