PIPES sodium salt

PIPES [piperazine-N,N′-bis(2-ethanesulfonic acid)] is frequently used as a buffering agent in biochemistry. It is an ethanesulfonic acid buffer developed by Good et al. in the 1960s. PIPES has a pKa near the physiological pH which makes it useful in cell culture work. It has been documented to minimize lipid loss when buffering glutaraldehyde histology in plant and animal tissues. Buffers can be prepared by adding a solution of base to PIPES free acid, titrating to the appropriate pH, or by mixing equimolar solutions of the monosodium salt and the disodium salt, titrating to the appropriate pH.