DNA does not migrate on gel

[mmorgan]

Originally Posted by thebetafemale

Interesting. I'm having a similar problem, only my ladder won't migrate either! I've been trying to do this gel isolation for days now and each time I run the (50 microliter) PCR, load the samples onto the gel, run it at 51 constant volts for 2.5 hours, and they don't migrate! The ladder just looks like a smear near the well and there appears to be bands, but they are just a few millimeters below the well. I'm using a different loading dye for the ladder than I am for my samples, and the dye migrates just fine. The DNA just won't. I know it's a 1% gel because I mix it up fresh each time and measure out the agarose exactly. What the hell am I doing wrong????

Are you adding the correct amount of TBE or TAE buffer. If you make up a gel with just water and no buffer you get a result similar to what you describe.

What current do you have at 51 Volts ??? I would guess that if the buffering is ok it would run at around 50 mA at 50V.

Check your buffers.

[pigfarmer]

Check the pH?