The 20X MES-SDS Running Buffer is formulated specifically for running proteins on Bis-Tris gels for separating small to medium-sized proteins under denaturing conditions in SDS-PAGE. When reconstituted from the 20X concentrate, this buffer maintains a stable pH of approximately 7.3. The MES-SDS Running Buffer enables faster and efficient resolution of well-defined protein bands in comparison to other running buffers in SDS-PAGE experiments.