50% glycerol
50% water
0.04% bromophenol blue (or until looks OK)
Use 2ul buffer with 10ul sample
100mM tris pH6.8
200mM DTT (or 10% BME)
4% SDS (electrophoresis grade)
0.2% bromophenol blue
20% glycerol
If storing at room temperature, omit reducing agent and add just prior to use.