HEPES is one of the best all-purpose buffers available for use in biological research. The molecule is zwitterionic at most biological pHs and is most effective as a buffer at pH 6.8 to 8.2. This buffer may be used in isoelectric focusing applications and as a buffer in the quantitative and selective measurement of antigen-antibody reactions. HEPES is reportedly superior to NaHCO3 in controlling pH in tissue and organ culture.
Not recommended for use with the Folin-Ciocalteu protein assay.