Ethyl methanesulfonate (EMS) is a mutagenic, teratogenic, and possibly carcinogenic organic compound with formula C3H8SO3. 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 O6-ethylguanine. During DNA replication, DNA polymerases that catalyze the process frequently place thymine, instead of cytosine, opposite O6-ethylguanine. Following subsequent rounds of replication, the original G:C base pair can become an A:T pair (a transition mutation). This changes the genetic information, is often harmful to cells, and can result in disease.
3D model (JSmol)
CompTox Dashboard (EPA)
|Molar mass||124.16 g/mol|
|Appearance||Clear colorless liquid|
|Density||1.1452 g/cm3 (22 °C)|
|Melting point||< 25 °C|
|Boiling point||85–86 °C (185–187 °F; 358–359 K) /10 mmHg(lit)|
|NFPA 704 (fire diamond)|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|what is ?)(|
- Merck Index, 11th Edition, 3782.