'Good' Buffer with pKa of 5.3-5.4?

[Shahram Mori]

mamber (mamber at synapse.bms.com) wrote:
: I need a buffer system capable of holding the pH (ideally) between 5.35
: and 5.4.  The pKa of MES (the 'Good' biological buffer with the lowest pH range
: as listed in the Sigma catalog) is 6.1, with a working range that doesn't hold
: well below 5.5 (as per my experiments).  I would be grateful to anyone that can
: recommend an appropriate buffer for my needs.  Thanks, SWM

: mamber at synapse.bms.com
How about Citric acid which has a Pka2 of 5.4. Maybe combining Maleic acid
and Tris-Hcl to the desired buffer.
Cheers,
 --
Shahram Mori					   _/\_
Program in Molecular Biology			  _\  /_
Dept. of chemistry and Biochemistry Box 3C	  \_  _/
NMSU  Las Cruces NM				    ||
88003