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 that PIPES disodium salt may help prevent lipid loss when buffering glutaraldehyde-fixed histological samples.
