ACES (N-(2-Acetamido)-2-aminoethanesulfonic acid) is a zwitterionic buffer. The working pH range of ACES buffer is 6.8-7.2.

Physicochemical Properties

Molecular Formula	C4H10N2O4S
Molecular Weight	182.20
Exact Mass	182.036
CAS #	7365-82-4
PubChem CID	81832
Appearance	White to off-white solid powder
Density	1.5±0.1 g/cm3
Melting Point	>220 °C (dec.)(lit.)
Index of Refraction	1.537
LogP	-3.24
Hydrogen Bond Donor Count	3
Hydrogen Bond Acceptor Count	5
Rotatable Bond Count	5
Heavy Atom Count	11
Complexity	217
Defined Atom Stereocenter Count	0
SMILES	S(C([H])([H])C([H])([H])N([H])C([H])([H])C(N([H])[H])=O)(=O)(=O)O[H]
InChi Key	DBXNUXBLKRLWFA-UHFFFAOYSA-N
InChi Code	InChI=1S/C4H10N2O4S/c5-4(7)3-6-1-2-11(8,9)10/h6H,1-3H2,(H2,5,7)(H,8,9,10)
Chemical Name	2-[(2-amino-2-oxoethyl)amino]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

References	[1]. Melissa D Mertzman, et al. Effect of surfactant concentration and buffer selection on chromatographic figures of merit in chiral microemulsion electrokinetic chromatography. Electrophoresis. 2004 Oct;25(18-19):3247-56. [2]. Rabindra N Roy, et al. Buffer Standards for the Physiological pH of the Zwitterionic Compound, ACES from 5 to 55°C. J Solution Chem. 2009 Apr 1;38(4):471-483.
Additional Infomation	N-(2-acetamido)-2-aminoethanesulfonic acid is a Good's buffer substance, pKa = 6.9 at 20 ℃. It is an ACES and an amino sulfonic acid. It is a tautomer of a 2-[(2-amino-2-oxoethyl)ammonio]ethanesulfonate.

Solubility Data

Solubility (In Vitro)	H2O: 41.67 mg/mL (228.70 mM)
Solubility (In Vivo)	Solubility in Formulation 1: 16.67 mg/mL (91.49 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	5.4885 mL	27.4424 mL	54.8847 mL
	5 mM	1.0977 mL	5.4885 mL	10.9769 mL
	10 mM	0.5488 mL	2.7442 mL	5.4885 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.