3 replies to this topic

[amisra2]

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

[bob1]

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).

[perneseblue]

and you can try electrolution or beta agarase treatment.

[BioMiha]

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