question about dna structure

[Giovanni Maga]

In article <3g1odq$spi at cronkite.ocis.temple.edu>,
willham at astro.ocis.temple.edu (Stephen J Williams) wrote:

> Hello,     
>   I have a question regarding the conformational changes induced by pH on 
> oligonucleotides.  I am using a Tris based buffer and am varying the pH 
> from 7.0 to 9.0.  Are there any conformational changes (like conversion from
> B-form to A-form with change in pH to a DNA duplex?  
> 
> Thank you 
> 
> Stephen Williams  at willham at astro.ocis.temple.edu

All I can say is that changing pH from 7 to 9 should improve the solubility
of your sample (the best for DNA is pH 8). If this is accompanied by
structural changes I do not know for sure. Actually I think that if you are
not changing other parameters like salt concentration or temperature you
should not worry too much about eventual conformational changes (but this
is always related to what you want to do with  your samples).
G.Maga
Biochemistry-University of ZŸrich Irchel