Ethyl methanesulfonate

Ethyl methanesulfonate
IUPAC name 1-Methylsulfonyloxyethane
Other names Ethyl mesylate Ethyl methanesulphonate
Identifiers
Abbreviations	EMS
CAS number	62-50-0 Y
PubChem	6113
ChemSpider	5887 Y
KEGG	C19239 N
ChEMBL	CHEMBL338686 Y
Jmol-3D images	Image 1
SMILES O=S(=O)(OCC)C
InChI InChI=1S/C3H8O3S/c1-3-6-7(2,4)5/h3H2,1-2H3 Y Key: PLUBXMRUUVWRLT-UHFFFAOYSA-N Y InChI=1/C3H8O3S/c1-3-6-7(2,4)5/h3H2,1-2H3 Key: PLUBXMRUUVWRLT-UHFFFAOYAM
Properties
Molecular formula	CH3SO3C2H5
Molar mass	124.16 g/mol
Appearance	Clear colorless liquid
Density	1.1452 g/cm3 (22 °C)
Melting point	< 25 °C
Boiling point	213–213.5 °C, 486.2-486.7 K
Hazards
NFPA 704	1 1 0
N (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Ethyl methanesulfonate (EMS) is a mutagenic, teratogenic, and possibly carcinogenic organic compound with formula CH₃SO₃C₂H₅. It produces random mutations in genetic material by nucleotide substitution; particularly by guanine alkylation. This typically produces only point mutations. It can induce mutations at a rate of 5x10^-4 to 5x10^-2 per gene without substantial killing. The ethyl group of EMS reacts with guanine in DNA, forming the abnormal base O-6-ethylguanine. During DNA replication, DNA polymerases that catalyze the process frequently place thymine, instead of cytosine, opposite O-6-ethylguanine. Following subsequent rounds of replication, the original G:C base pair can become an A:T pair. This changes the genetic information, is often harmful to cells, and can result in disease.

EMS is often used in genetics as a mutagen. Mutations induced by EMS can then be studied in genetic screens or other assays.