0.5M HEPES Buffer

HEPES is included in the zwitterionic Good buffer group. It is used for freezing protein solutions. The increase in acidity as a result of freezing observed in many buffers is negligible in the presence of HEPES buffer. HEPES protects enzymes and coenzymes from denaturation and inactivation during freeze-drying and subsequent storage. HEPES has wide usage in cell culture media. However, it has also been noted to promote the development of certain cell lines. Compared to Tris buffers, HEPES has a lower temperature dependence. This buffer does not form complexes with divalent metal ions, in some cases acting as a cofactor or activator for certain enzymes (eg Mg2+ for Benzonase). While HEPES shows low absorbance in the UV region, it may give false positive results as it interferes with the Lowry protein method. HEPES buffers can be prepared by mixing equimolar solutions of HEPES and HEPES-Na.

HEPES has been described as one of the best all-purpose buffers available for biological research.1 Similar to many amino acids, HEPES is zwitterionic at most biological pHs. It's effective as a buffer in the pH range of 6.8 to 8.2, and in concentrations between 10 millimolar to 25 millimolar. HEPES is one of the most effective buffers in the important physiological pH range of 7.2 to 7.6. HEPES has been utilized extensively for research and commercial applications in the cell culture and tissue culture industries. Other large application areas include cosmetics and skin care, electronics and computer chip manufacturing.

1. N.E. Good, et al., Biochemistry, 5, 467 (1966).

• Size: 100mL, 250mL
• Sterile (Dnase, Rnase free), 0.22um filtered to ensure upmost quality
• Expiration date: 2 years from manufacturing date