MES SDS Running Buffer is formulated for running ExpressPlusᵀᴹ and SurePAGEᵀᴹ, Bis-Tris gels. This buffer is ideal for separating small- and medium- sized proteins. For separation of large- to medium- sized proteins, Tris-MOPS SDS buffer (M00138) is recommended. Reconstitute with 1000 ml deionized water to make 1X running buffer per pack of powder. Do not use acid or base to adjust the pH.