Glucose in alkaline lysis! (was: Re: Merlin maxiprep help?)

[Tom Anderson]

On Mon, 23 Jul 2007, DK wrote:

> In article <vsbni.146$BJ1.116 from newsfe03.lga>, dk from no.email.thankstospam.net (DK) wrote:
>
> >Looking at the maxi prep protocol reminded me of the reason there is
> >glucose in the cell resuspension solution.
> >
> >This can be a fun little puzzle:
> >
> >Do YOU know why 50 mM glucose is included in "P1"?
>
> OK, here is the answer: glucose has pKa at 12.5 (I think it is its
> aldehyde group), so glucose inclusion provides protection against
> irreversible DNA denaturation during alkaline lysis step. This is
> particularly important in large scale preps because, due to viscosity,
> mixing is very difficult and good neutralization without shearing
> chromosomal DNA can take very long time.

Interesting idea. Not to disrespect your authority, but do you have a
citation for that? It has a faint whiff of urban legend to it ...

tom

-- 
Tom Anderson, MRC Laboratory for Molecular Cell Biology, UCL, London WC1E 6BT
(t) +44 (20) 76797264   (f) +44 (20) 76797805   (e) thomas.anderson from ucl.ac.uk