0.2M MOPS, pH 7.0, is supplied by HiMedia. It is available in the form of a colourless solution with a pH in the range of 6.9 to 7.1. MOPS is a morpholino propanesulfonic acid, a structural analog to MES, the ethanesulfonic acid (first introduced by Good et al.) Both series of buffers were developed to meet the following criteria: midrange pKa, maximum water solubility and minimum solubility in all other solvents, minimal salt effects, minimal change in pKa with temperature chemically and enzymatically stable, minimal absorption in visible or UV spectral range, and reasonably easily synthesized. The pKa is 7.2 at 25C. It is advisable to store this product room temperature (15-25C). 0.2M MOPS Solution is composed of extra pure molecular biology grade MOPS and aseptically filtered.

MOPS is a zwitterionic buffer which was developed by Good et al., 1966. It is structurally analogous to MES and has negligible metal binding capacity. 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 be used as an electrophoresis buffer for agarose gel electrophoresis of RNA.