HEPES is a non-volatile zwitterionic chemical buffer extensively used in cell culture. HEPES is an effective buffer at pH 6.8 to 8.2. HEPES is also a potent inducer of lysosomal biogenesis.

Physicochemical Properties

Molecular Formula	C8H18N2O4S
Molecular Weight	238.30
Exact Mass	238.098
CAS #	7365-45-9
Related CAS #	HEPES sodium;75277-39-3;HEPES-d18;203805-87-2
PubChem CID	23831
Appearance	White to off-white solid powder
Density	1.3±0.1 g/cm3
Melting Point	234-238 °C
Index of Refraction	1.543
LogP	-2.67
Hydrogen Bond Donor Count	2
Hydrogen Bond Acceptor Count	6
Rotatable Bond Count	5
Heavy Atom Count	15
Complexity	267
Defined Atom Stereocenter Count	0
InChi Key	JKMHFZQWWAIEOD-UHFFFAOYSA-N
InChi Code	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)
Chemical Name	2-[4-(2-hydroxyethyl)piperazin-1-yl]ethanesulfonic acid
HS Tariff Code	2934.99.9001
Storage	Powder-20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month
Shipping Condition	Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Biological Activity

ln Vitro	For a minimum of three months, HEPES preserves titanium's superhydrophilicity, which leads to an ongoing retention of osteoconductivity and bioactivity[1]. In cultivated RAW264.7 cells, HEPES promotes lysosome formation, modifies the cytoplasmic-nuclear distribution of MiT/TFE, and modifies global cellular transcriptional patterns. These actions culminate in the activation of a MiT/TFE-dependent lysosomal-autophagic gene network[3].
References	[1]. Nonvolatile buffer coating of titanium to prevent its biological aging and for drug delivery. Biomaterials. 2010;31(18):4818-4828. [2]. An experimental charge density of HEPES. Acta Crystallogr B. 2010;66(Pt 4):482-492. [3]. HEPES activates a MiT/TFE-dependent lysosomal-autophagic gene network in cultured cells: A call for caution. Autophagy. 2018;14(3):437-449.
Additional Infomation	2-[4-(2-hydroxyethyl)piperazin-1-yl]ethanesulfonic acid is a HEPES that is ethanesulfonic acid in which one of the methyl hydrogens is replaced by a 4-(2-hydroxyethyl)piperazin-1-yl group. A Good's buffer substance, pKa = 7.55 at 20 ℃. It is a HEPES and an organosulfonic acid. It is a conjugate acid of a 2-[4-(2-hydroxyethyl)piperazin-1-yl]ethanesulfonate. It is a tautomer of a 2-[4-(2-hydroxyethyl)piperazin-4-ium-1-yl]ethanesulfonate. Hydroxyethylpiperazine Ethane Sulfonic Acid is a zwitterionic biological buffer used in cell culture to maintain physiological pH. It is less affected by changes in carbon dioxide concentrations than bicarbonate buffers. A dipolar ionic buffer.

Solubility Data

Solubility (In Vitro)	H2O: 250 mg/mL (1049.10 mM)
Solubility (In Vivo)	Solubility in Formulation 1: 100 mg/mL (419.64 mM) in PBS (add these co-solvents sequentially from left to right, and one by one), clear solution; with sonication.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	4.1964 mL	20.9820 mL	41.9639 mL
	5 mM	0.8393 mL	4.1964 mL	8.3928 mL
	10 mM	0.4196 mL	2.0982 mL	4.1964 mL

*Note: Please select an appropriate solvent for the preparation of stock solution based on your experiment needs. For most products, DMSO can be used for preparing stock solutions (e.g. 5 mM, 10 mM, or 20 mM concentration); some products with high aqueous solubility may be dissolved in water directly. Solubility information is available at the above Solubility Data section. Once the stock solution is prepared, aliquot it to routine usage volumes and store at -20°C or -80°C. Avoid repeated freeze and thaw cycles.