FW: Ethanol in my RNA/TE buffer

redeamer alion85 at hotmail.com
Thu Jun 24 19:07:06 EST 2004


Hi Deanne!

> Adding ethanol (like 250% of the buffer volume) makes nucleic acids
> precipitate out of buffered solution - right?  

I prefer to precipitate the RNA with 2.5 volumes of isopropanol : 5M
NH4OAc (5:1) at room temperature. That is much more effective than
ethanol one. Afterwards, i wash the transparent RNA pellet with 70%
EtOH.

> A LOT of left over ethanol will prevent nucleic acids from fully
> dissolving back into the buffer.  A LITTLE  will probably evaporate out
> of the TE solution.

Well, if you saw the pellet and didn't use any coprecipitant then you
have quite a lot of RNA. Residual EtOH won't heart you if the
applications (assays) do not require much RNA, say if you dilute RNA
20 fold or 50 fold. Nothing to worry about. Typically it is not a
problem.

But if you think or have intrinsic feeling that you should actually
dry it completely. Just reprecipitate the RNA :)



---> Drew



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