MOPS

For other uses, see Mops.

MOPS (3-(N-morpholino)propanesulfonic acid) is a buffer introduced in the 1960s, one of the twenty Good's buffers. It is a structural analog to MES,^[1] and like MES, its structure contains a morpholine ring. HEPES is a similar pH buffering compound that contains a piperazine ring. With a pK_a of 7.20, MOPS is an excellent buffer for many biological systems at near-neutral pH.

MOPS

Names
Preferred IUPAC name 3-(Morpholin-4-yl)propane-1-sulfonic acid
Other names 3-(N-Morpholino)propanesulfonic acid, 3-Morpholinopropanesulfonic acid, 3-N-Morpholino propansulfonic acid, 4-Morpholinepropanesulfonic acid
Identifiers
CAS Number	1132-61-2 (free acid) Y 71119-22-7 (sodium salt) N
3D model (JSmol)	Interactive image
ChemSpider	63972 N
ECHA InfoCard	100.013.162
PubChem CID	70807 2723950
UNII	273BP63NV3 Y
CompTox Dashboard (EPA)	DTXSID4044371
InChI InChI=1S/C7H15NO4S/c9-13(10,11)7-1-2-8-3-5-12-6-4-8/h1-7H2,(H,9,10,11) N Key: DVLFYONBTKHTER-UHFFFAOYSA-N N InChI=1/C7H15NO4S/c9-13(10,11)7-1-2-8-3-5-12-6-4-8/h1-7H2,(H,9,10,11) Key: DVLFYONBTKHTER-UHFFFAOYAN
SMILES C1COCCN1CCCS(=O)(=O)O
Properties
Chemical formula	C7H15NO4S
Molar mass	209.26 g·mol−1
Hazards
GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H315, H319, H335
Precautionary statements	P261, P264, P271, P280, P302+P352, P304+P340, P305+P351+P338, P312, P321, P332+P313, P337+P313, P362, P403+P233, P405, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

Applications

MOPS is frequently used as a buffering agent in biology and biochemistry. It has been tested and recommended for polyacrylamide gel electrophoresis.^[2] Usage above 20 mM in mammalian cell culture work is not recommended.^[3] MOPS buffer solutions become discolored (yellow) over time, but reportedly slight discoloration does not significantly affect the buffering characteristics.^[4]

See also

• CAPS
• HEPPS
• Tris
• Common buffer compounds used in biology

References

1. Good, Norman E.; Winget, G. Douglas; Winter, Wilhelmina; Connolly, Thomas N.; Izawa, Seikichi; Singh, Raizada M. M. (1966). "Hydrogen Ion Buffers for Biological Research". Biochemistry. 5 (2): 467–77. doi:10.1021/bi00866a011. PMID 5942950.
2. Thomas, J; Hodes, ME (1981). "A new discontinuous buffer system for the electrophoresis of cationic proteins at near-neutral pH". Analytical Biochemistry. 118 (1): 194–6. doi:10.1016/0003-2697(81)90178-0. PMID 6278979.
3. Eagle, H. (1971). "Buffer Combinations for Mammalian Cell Culture". Science. 174 (4008): 500–3. Bibcode:1971Sci...174..500E. doi:10.1126/science.174.4008.500. PMID 5110427. S2CID 29876583.
4. "Boston BioProducts - MOPS Buffer (1 M, pH 7.4)".

External links

• Sigma Aldrich Buffer Calculator - Useful tool to calculate weight, volume, or concentration from molecular weight.
• Recipe for MOPS buffer on OpenWetWare