Wanted: buffer for pH 2.5-3!!

[Dima Klenchin]

In article 
<Pine.SOL.3.91.960716142607.28951C-100000 at godzilla4.acpub.duke.edu>,
   Namjin  Chung <nc1 at acpub.duke.edu> wrote:
->
->Dear Netters,
->I'm working with an uncharacterized yeast enzyme activity, and it seems 
->to have activity around pH 2.5 and 3.0.  Currently I'm using Citric Acid 
->and Citrate-Phosphate buffers to get a decent result.  The activity is, 
->however, inconsistent-standard deviation is high from experiment to exp.
->
->I guess that harsh pH like 2.5 itself might have killed the enzyme 
->activity to give varying results, but is that possible?  If pH itself 
->were the matter here, it should always kill the enzyme, and if there is 
->the enzyme activity around this pH, the enzyme should survive at this 
pH.
->
->So I suspect the buffers (citrate and citrate-phosphate) may not be good 
->at this pH.  Is there anyone who had this kind of experience, and/or who 
->could recommend a good buffer for this pH range (2.5-3.0).  Thank you in 
->advance for comments.  

I wouldn't blame buffers for that. Citrate-phosphate is exactly what
I'd use for this range. And they are perfectly "good" and stable.

- Dima