Why use imidazole as a buffer? - Imidazole Buffer (May/14/2002 )

Why is imidazole such a popular buffer?  I am trying to use an amino spe phase to extract indole acetic acid (IAA) from plant leaf tissue.  Very little IAA is sticking during during my sample load.  The sample is in imidazole buffer.  The original extraction procedure using imidazole was developed elsewhere.  I would like to change the buffer, but before I do, I would like to know what is special about imidazole as a buffer and why it was likely chosen for this application.

I can only guess but it may be the difference between the pK's of the two compounds imidazole = 6.92 and your auxin = 4.75. This may allow the auxin to bind to the column at pH X while the imidazole flows through.

I don't like Imidazole and quite have good luck purifying auxins using HEPES buffer pH 7.0

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