Gel Extracting a 15kb Band? - Quick and Easy method (Nov/15/2010 )

Hi

I am trying to extract a 15kb Band from agarose gel for ligation. I have used the Qiaquick Gel Extraction Kit, and it didn't work. The kit says it is designed to extract and purify DNA of 70bp to 10kB so I am not surprised. But is there another kit or another method out there that's easy, quick and cheap for larger fragments?

Any help would be much appreciated! Thank you

There's plenty of methods out there for ligation in the gel. Otherwise you could try eluting onto DE81 paper (see Sambrook et al Molecular cloning: a laboratory manual), or "freeze 'n' squeeze" (freezing the gel, spinning out the agarose and using the supernatant).

and you can try electrolution or beta agarase treatment.

Or you could just use a genomic DNA extraction kit. It's designed for long DNA fragments.