HEPES, chemically known as 4-(2-hydroxyethyl)piperazine-1-ethanesulfonic acid, functions as a zwitterionic N-substituted aminosulfonic acid buffer, possessing remarkable buffering capacity within the pH range of 6.8-8.2 (with a pKa of 7.48 at 25°C). Widely recognized for its versatility, it is heavily utilized in cell biology, biochemical, and biological research

endeavors. One of its notable characteristics is its neutrality towards metal ions, making it a preferred "non-coordinating buffer" that can be safely used in solutions containing metals without compromising their activity.