SDS gel-loading buffer (2X)

100 mM Tris-Cl (pH 6.8)

4% (w/v) SDS (sodium dodecyl sulfate; electrophoresis grade)

0.2% (w/v) bromophenol blue

20% (v/v) glycerol

200 mM DTT (dithiothreitol)

Store the SDS gel-loading buffer without DTT at room temperature. Add DTT from a 1 M stock just before the buffer is used.

200 mM β-mercaptoethanol can be used instead of DTT.