5X Protein Loading Buffer is a reducing sample buffer for SDS-polyacrylamide gel electrophoresis (SDS-PAGE). 5X Protein Loading Buffer contains 1.0M TrisHCl (pH 8.5), 8% (W/v) lithium dodecyl sulfate, 40% (v/W) glycerol, 2mM EDTA, DTT and tracking dye in distilled/deionized water.