Buffering Phenol: pH directly

[the End]

Jim Owens writes:

> I have heard that it is  possible to measure the pH of an organic solution, 
> but a pH meter or the pH papers will not give an accurate measure.

It is indeed.

For Phenol:
Mix 2 ml of organic phase with 8 ml of methanol and 10 ml of water. Use
a pH meter.

For Phenol/CIA:
Mix 2 ml of organic pahse with 5 ml methanol and 13 ml of water.

I think the problems mentioned contribute greatly to the variability of 
organic extractions. I prefer to substitute a Proteinase K digest for 
phenol extraction whenever feasible.

Jim
J. E. Graham 
Biology and Chemistry Departments 
Indiana University Bloomington