CHES (buffer)

CHES (N-cyclohexyl-2-aminoethanesulfonic acid) is a buffering agent. CHES buffers have a useful range of pH 8.6–10.^[1]

CHES

Names
Preferred IUPAC name 2-(Cyclohexylamino)ethane-1-sulfonic acid
Other names N-Cyclohexyl-2-aminoethanesulfonic acid; N-Cyclohexyltaurine
Identifiers
CAS Number	103-47-9 Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:44302
ChemSpider	60260 Y
DrugBank	DB03309 Y
ECHA InfoCard	100.002.832
MeSH	2-(N-cyclohexylamino)ethanesulfonic+acid
PubChem CID	66898
UNII	71X53V3RZ1 Y
CompTox Dashboard (EPA)	DTXSID7059274
InChI InChI=1S/C8H17NO3S/c10-13(11,12)7-6-9-8-4-2-1-3-5-8/h8-9H,1-7H2,(H,10,11,12) Y Key: MKWKNSIESPFAQN-UHFFFAOYSA-N Y InChI=1/C8H17NO3S/c10-13(11,12)7-6-9-8-4-2-1-3-5-8/h8-9H,1-7H2,(H,10,11,12) Key: MKWKNSIESPFAQN-UHFFFAOYAH
SMILES O=S(=O)(O)CCNC1CCCCC1
Properties
Chemical formula	C8H17NO3S
Molar mass	207.29 g·mol−1
Acidity (pKa)	9.3
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

It typically appears as a white crystalline powder.

Effect of impurities

Commercial prep of CHES (and other sulfonylethyl buffers like MES, BES, and PIPES) can contain a contaminant oligo(vinylsulfonic acid) (OVS), which is a polyanionic mimic of RNA, and can be a potent (pM) inhibitor of RNA binding proteins and enzymes.^[2]