391338

HEPES

≥99% dry basis (titration), crystalline powder, amniosulfonic acid buffer

• Synonym(s): HEPES, N-2-Hydroxyethylpiperazine-Nʹ-2-ethanesulfonic Acid, 4-(2-Hydroxyethyl)piperazine-1-ethanesulfonic acid, N-(2-Hydroxyethyl)piperazine-N′-(2-ethanesulfonic acid)
• Empirical Formula (Hill Notation): C₈H₁₈N₂O₄S
• CAS Number: 7365-45-9
• Molecular Weight: 238.30
• Beilstein/REAXYS Number: 883043
• MDL number: MFCD00006158
• UNSPSC Code: 12352106
• NACRES: NA.25

Properties

• Product Name: HEPES, ULTROL^® Grade, ≥99% dry basis (titration), zwitterionic N-substituted aminosulfonic acid buffer
• description: Merck USA index - 14, 4654
• Quality Level: 100
• assay: ≥99% dry basis (titration)
• form: crystalline powder
• manufacturer/tradename: Calbiochem^®
• storage condition: OK to freeze
• color: white
• useful pH range: 6.8-8.2
• pKa (25 °C): 7.5
• solubility: water: 1 M
• anion traces: chloride (Cl^-): ≤0.01%; sulfate (SO₄^2-): ≤0.05%
• cation traces: Na: ≤0.1%; heavy metals: ≤1 ppm
• shipped in: ambient
• storage temp.: 15-25°C
• SMILES string: OCCN1CCN(CC1)CCS(O)(=O)=O
• InChI: 1S/C8H18N2O4S/c11-7-5-9-1-3-10(4-2-9)6-8-15(12,13)14/h11H,1-8H2,(H,12,13,14)
• InChI key: JKMHFZQWWAIEOD-UHFFFAOYSA-N

Description

General description

A zwitterionic N-substituted aminosulfonic acid buffer. HEPES has its maximum buffering capacity very near the pH of mammalian tissue fluids (pK_a of 7.31 at 37°C). Exhibits no metal binding and has a small temperature dependent ΔpKa of -0.014/°C.

Absorbance (1.0 M, H₂O, 260 nm):≤0.05.

Absorbance (1.0 M, H₂O, 280 nm): ≤0.04

Warning

Toxicity: Irritant (B)

Reconstitution

Following reconstitution, store at room temperature (20°C). Stock solutions are stable for up to 6 months at 20°C.

Legal Information

CALBIOCHEM is a registered trademark of Merck KGaA, Darmstadt, Germany

ULTROL is a registered trademark of Merck KGaA, Darmstadt, Germany

Safety Information

• Storage Class: 13 - Non Combustible Solids
• wgk_germany: WGK 1
• flash_point_f: Not applicable
• flash_point_c: Not applicable