Merck, H3784-1KG, HEPES sodium salt

HEPES, or 4-(2-hydroxyethyl)piperazine-1-ethane-sulfonic acid, is a zwitterionic N-substituted aminosulfonic acid buffer with a remarkable pH buffering capacity between 6.8 and 8.2 (pKa of 7.48 at 25°C). Widely recognized for its versatility, HEPES is extensively employed in cell biology, biochemical, and biological research. Notably, its neutrality towards metal ions makes it a preferred choice for solutions with metal ions, acting as a \non-coordinating buffer.\ In cell culture, HEPES excels in maintaining stable physiological pH even amidst fluctuating carbon dioxide concentrations, outperforming bicarbonate buffers (NaHCO₃). Moreover, HEPES showcases valuable properties in various biological and biochemical processes, such as isoelectric focusing for protein separation and minimal interference in DNA-restriction enzyme reactions, making it indispensable across diverse research applications, including immunoprecipitation, cell lysis, and live cell imaging. Its versatility, exceptional buffering capacity, and minimal interaction with molecules establish HEPES as a key tool in various research domains.