DNA purifeication from

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Tegrion's picture
DNA purifeication from

Hi, dear colleagues!

I try to do plasmid construction at first time and get stack with lack of reactives.
Due to a protocol for purification DNA fragments from gel after restriction, i should to excise DNA-containing gel and put it in "NaI" (NaI 6.6M, Na2SO3 16 mM, Cresol red 0.25 mM). But... We don't have NaI at them moment.

Could you tell, can i substitute NaI by KI in equal concentration?

And if you don't mind, could explain the mechanism of  agarose gel dissolving in this mix?

Thank you!

Ivan Delgado
Ivan Delgado's picture
Hi Tegrion,

Hi Tegrion,

I wished I could help you but I've never used NaI for DNA purification from gels. Hopefully someone else can help you with this.

By best estimation is that you cannot use KI instead of NaI.


jackclj's picture
I'm pretty sure it would

I'm pretty sure it would work. As far as I understand this, all you need is a salt that will disolve in free iodine and a monovalent cation when in solution. However I don't know if you would need to replace the Na2SO3 with K2SO3. I don't see how it would make a difference but maybe it does... As for the mechanism, I don't know precisely but I think sodium Iodine keeps everything except nucleic acid into solution while you precipitate with isopropanol. If you don't have anything more important to do, I would definitely try it