TBE precipitation

[XL]

I am running a lot of DNA sequencing gels in my lab. One of the reagents we
use routinely is the TBE. We usually make a 10X stock and make dilution from
there. As many of you may already notice that 10XTBE will precipitate after
the stock is used/opened.  I am trying to get some chemistry explanations
about this precipitation. Is it because of the solubility, pH or chemical
reactions with air?  Thank you.









--
Xiaoyang Liu
Facility Scientist
Macromolecular Characterization Facility
The University of Connecticut
184 Auditorium Road, U-149
Storrs, Connecticut 06269-3149
Tel: 860-486-5024
Fax: 860-486-5005
e-mail: x_liu at biotek.mcb.uconn.edu