One of the original Good’s buffers, MES Buffer has a pKa value near physiological pH. It is not absorbed through cell membranes, and it is essentially transparent to UV light. MES Buffer is a zwitterionic buffer and is primarily used as a running buffer for resolving very small proteins on bis-tris gels. Also used in cation-exchange chromatography and as a biological buffer in plant cell cultures, MES solutions can be prepared to the desired pH by titrating the free acid with sodium hydroxide.
