MES

MES (2-Morpholinoethanesulphonic acid) is a kind of amphoteric ion buffer, the buffer capacity ranging pH 5.5-7.0. As a Good's buffer, MES is widely used in biochemistry and molecular biology experiments, such as cell culture, enzyme activity determination, electrophoresis and protein studies^[1][2]. In Vitro:MES is a zwitterionic buffer and can provide effective buffering capacity at around pH 6.15. The pKa value of MES changes with temperature, so the change of its pKa value needs to be considered when using it at different temperatures^[1].
MES shows good buffering properties in biological experiments, exhibits poor affinity with metal ions (binding constants at 20 ℃ and 0.1 M: Mg²⁺, 0.8; Ca²⁺, 0.8; Mn²⁺, 1.7), thereby can be used in studies involving metal ions^[1].