HEPES sodium salt
[CAS# 75277-39-3]

Identification

• Classification: Chemical reagent >> Organic reagent >> Sulfonate / sulfinate
• Name: HEPES sodium salt
• Synonyms: Sodium 4-(2-hydroxyethyl)piperazin-1-ylethanesulphonate; 2-[4-(2-Hydroxyethyl)-1-piperazine]ethanesulfonic acid sodium salt
• Molecular Formula: C₈H₁₇N₂NaO₄S
• Molecular Weight: 260.28
• CAS Registry Number: 75277-39-3
• EC Number: 278-169-7
• SMILES: C1CN(CCN1CCO)CCS(=O)(=O)[O-].[Na+]

Properties

• Solubility: 1 M (water 20 °C)
• Melting point: 234 °C

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H302-H315-H319-H335
• Safety Statements: P261-P305+P351+P338

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Specific target organ toxicity - single exposure	STOT SE	3	H335
Skin irritation	Skin Irrit.	2	H315
Eye irritation	Eye Irrit.	2	H319

Discovery and Applications

HEPES sodium salt, chemically known as N-(2-hydroxyethyl)piperazine-N'-(2-ethanesulfonic acid) sodium salt, is a zwitterionic organic chemical buffer. It is widely used in biological and biochemical research to maintain the pH of cell culture and protein purification solutions. The substance has the molecular formula C8H17N2NaO4S and offers several advantages over other buffers due to its effective buffering capacity near physiological pH.

The discovery of HEPES sodium salt can be traced back to Good buffers, a series of compounds developed by Norman Good and his colleagues in the 1960s. These buffers were designed specifically for biological research to address the limitations of traditional buffers. HEPES is one of the most prominent Good buffers, which was synthesized to provide a stable pH environment with minimal interaction with biological systems. Later, the sodium salt form of HEPES was introduced to improve its solubility and ease of use in various experimental setups.

One of the main applications of HEPES sodium salt is cell culture. Maintaining a stable pH is essential for the survival and growth of cells in vitro. HEPES sodium salt is particularly effective in this regard because its pKa is close to physiological pH (7.4), which makes it an excellent buffer for maintaining pH values ​​in the range of 6.8 to 8.2. Its buffering capacity remains stable over a wide temperature range, which is very beneficial for experiments involving temperature fluctuations.

During protein purification, maintaining a stable pH is essential to preserve protein structure and function. HEPES sodium salt is often used in buffer solutions during chromatography and electrophoresis. It has minimal interference with biochemical reactions, ensuring that proteins remain stable and active, thereby facilitating accurate and efficient purification.

HEPES sodium salt is frequently used in molecular biology protocols, including enzymatic reactions, DNA/RNA extraction, and PCR. Its ability to maintain a stable pH helps optimize reaction conditions, resulting in higher yields and more reliable results. In addition, HEPES does not significantly absorb UV light, making it suitable for use in spectrophotometric assays that require accurate measurement of absorbance.

In medical and pharmaceutical research, HEPES sodium salt is used in a variety of applications, including drug formulation and drug delivery. Its biocompatibility and stability make it a suitable buffer in the development of pharmaceutical solutions and injectable drugs. In addition, HEPES buffered solutions are used in diagnostic assays and as a component of culture media for tissue engineering and regenerative medicine.

In addition to biological applications, HEPES sodium salt is also used in environmental and chemical research. Its buffering properties can be used in research involving chemical reactions and environmental monitoring. For example, it is used to prepare buffer solutions for pH-sensitive chemical analyses and experiments.

References

2021. Determination of Solubility of 4-(2-Hydroxyethyl)-1-piperazineethanesulfonic Acid and its Sodium Salt in Acetonitrile and Voltammetric Investigation of Sulphonamide Drugs in Different Solvents in Their Absence and Presence. Journal of Solution Chemistry, 50(1).
DOI: 10.1007/s10953-020-01047-2

2024. Rapid method for screening of both calcium and magnesium chelation with comparison of 21 known metal chelators. Journal of biological inorganic chemistry : JBIC : a publication of the Society of Biological Inorganic Chemistry, 29(7).
DOI: 10.1007/s00775-024-02078-6

2023. Calcium-assisted sortase A cleavage of SUMOylated metallothionein constructs leads to high-yield production of human MT3. Microbial Cell Factories, 22(1).
DOI: 10.1186/s12934-023-02134-x