Should I use LMT Agarose to purify genomic DNA? Help please! - (Mar/29/2006 )

HI

I need to purify gDNA that is already extracted but highly contaminated with a toxic metal (As).
I saw in several papers people ran the DNA on low melting temp. agarose to purify it.

What's the advantage of LMT over regular agarose? (i thought LMT gives higher resolution), but I have gDNA.
And what LMT concentration should I use?
Thanks!!

it depends a lot on what you are planning on doing next. If you need unsheared DNA, then large DNA fragments will not run on either type of agarose (unless you use pulsed field or FIGE). If you are just planning on doing PCR of 5Kb fragments, then there are probably easier ways than running it on a gel. Can't you just dialyze the DNA against high volume buffer at 4C overnight? I've never had any luck with LMP agarose gels -- I gave up on them the last time I tried to run an 0.5% LMP gel for sizing DNA fragments, and just cloned the cut DNA. Cloning without sizing worked very well.