MES buffer in dialyzation - MES or any alternative for MES? (May/17/2002 )

Hi!All,
 I prepare to biotinylate  a protein.According to the protocol,the MES (0.1M,PH5.5)is required in the process.But in China,the order time is too long and we need it  badly,and I don't know could we use
any other alternative ? I really appreciate your help.
   

Please use cacodylate buffer ( sodium arsenate) set at pH 4.9.

Sam Brilliant
Ph.D. Rescue Team
A Division of DSTF-Global
http://www.dstf.bigstep.com