in phenol/chloroform purification of nucleic acid, do you need to control pH of - (Jul/14/2006 )

There are several cool posts on this forum describing the nitty gritty of nucleic acid purification with phenol/chloroform (e.g. http://www.protocol-online.org/forums/inde...showtopic=9820). If you want to extract DNA pH should be close to 8.

Now, do you need to control pH of chloroform in the second step?

And what's the advantage of using isoamyl+chloroform instead of just chloroform?

Ta, j

chloroform pH shouldn't be checked as if i'm correct, it's not an acid or a base... (HCCl3) ...
Using IAA is for stabilisation of the solution of chlororofm.
But it's possible to use just chloroform

for DNA extraction the phenol must be pH 8.
chloroforme is always used with IAA mixture 24-1

for DNA extraction phenol must be pH 8.

You can also do only one extraction using phenol:chloroform:IAA= 24:23:1
In this case you don't need to adjust the pH

Thanks for the replies, esp. Fred33 - you know your stuff

Ciao, j