M5057 Sigma-Aldrich

MES sodium salt

BioReagent, ≥99% (titration), crystalline

Synonym: 2-(N-Morpholino)ethanesulfonic acid sodium salt, 4-Morpholineethanesulfonic acid sodium salt

  • CAS Number 71119-23-8

  • Empirical Formula (Hill Notation) C6H12NNaO4S

  • Molecular Weight 217.22

  •  Beilstein/REAXYS Number 3765682

  •  EC Number 275-203-2

  •  MDL number MFCD00065473

  •  eCl@ss 32129211

  •  PubChem Substance ID 24896974

  •  NACRES NA.25



Related Categories Biochemicals and Reagents, Biological Buffers, Buffers A to Z, Good’s Buffers
Quality Level   300
product line   BioReagent
assay   ≥99% (titration)
form   crystalline
pH   8.9-10.1 (1% in water)
useful pH range   5.5 - 6.7
pKa    6.1
solubility   water: 0.5 g/mL, clear, colorless
Featured Industry   Diagnostic Assay Manufacturing
storage temp.   room temp
SMILES string   [Na+].[O-]S(=O)(=O)CCN1CCOCC1
InChI   1S/C6H13NO4S.Na/c8-12(9,10)6-3-7-1-4-11-5-2-7;/h1-6H2,(H,8,9,10);/q;+1/p-1


General description

MES is one of the so-called "Good" buffers developed for biological applications. This product is tested for trace ions. A buffer using MES free acid can be prepared by titrating the free acid with sodium hydroxide to the desired pH (pKa=±-1). Alternatively, volumes of equimolar solutions of MES free acid and MES sodium can be mixed to attain the desired pH. Standard mixing tables using stock solutions to prepare a buffer of a given pH have been published.


MES sodium salt has been used:
• To achieve the required density and stretching of DNA fibers during melting of agarose plugs containing genomic DNA
• To equilibrate the Balch homogenizer chamber and to prevent sample hydrolysis before sample homogenization


10, 25, 100 g in poly bottle

Preparation Note

MES Sodium is soluble in water, giving a clear colourless solution at 25g in 50mL water (approximately 2.3M). The pH of a solution should be between 9 and 10 depending on concentration. Solutions should be stable at 2-8°C for months. Sterilization should be by filteration through 0.2μm filters. Autoclaving is not recommended. If buffers must be nuclease-free, it is best to treat the water first, and then add the buffer solids after autoclaving. When MES solutions are autoclaved, they turn yellow (although pH does not change measurably). The identity of the yellow breakdown product is unknown.

Other Notes

Easily compare specifications for MES sodium salt products with the MES sodium salt specification table.

Safety & Documentation

Safety Information

Personal Protective Equipment 
NONH for all modes of transport
WGK Germany 
Flash Point(F) 
Not applicable
Flash Point(C) 
Not applicable


Certificate of Analysis (COA)

Please Enter a Lot Number

Certificate of Origin (COO)

Please Enter a Lot Number

pHast Pack
Protocols & Articles

Related Content

BioUltra Biological Buffers

A buffer, as defined by Van Slyke [1], is "a substance which by its presence in solution increases the amount of acid or alkali that must be added to cause unit change in pH". Buffers are thus very i...
Keywords: Absorption, Adsorption, Biochemistry, Biological Buffers, Biological processes, Buffers, PAGE

Peer-Reviewed Papers


Related Products

Technical Service:

Our team of scientists has experience in all areas of research including Life Science, Material Science, Chemical Synthesis, Chromatography, Analytical and many others.

Bulk Ordering & Pricing:

Need larger quantities for your development, manufacturing or research applications?