Synonym(s): 4-(2-Hydroxyethyl)-1-piperazineethanesulfonic acid Formula: C8H18N2O4S Formula weight: 238.31 Purity: 99% CAS Number: 7365-45-9 Harmonized Tariff Code:  2933.59

HEPES (N-[2-Hydroxyethyl]piperazine-N'-[2-ethanesulfonic acid]), Free Acid Also known as N-[2-Hydroxyethyl]piperazine-N'-[2-ethanesulfonic acid]. A zwitterionic "Good Buffer" because it has a pKa value near physiological pH