MOPS is a zwitterionic buffer which was developed by Good et al., 1966. It is structurally analogous to MES and it's metal binding capacity is negligible. As the pKa value of MOPS is 7.20 it is an excellent buffer for many biological systems at near-neutral pH.
MOPS is extensively used as a buffering agent in molecular biology and biochemistry. It has been tested and recommended for use in polyacrylamide gel electrophoresis. MOPS can be used in many bioanalytical methods like isoelectric focusing, protein assays and in X-ray crystallographic studies. MOPS can also used as an electrophoresis buffer for agarose gel electrophoresis of RNA.