Western Buffer B (formerly 2X Sample Buffer)

This buffer is used to dilute the samples for Western Blot assays. Typically, the samples are in Western Buffer A and are diluted 1:1 with Western Buffer B and loaded on the gel.

To make 100ml

• 4g SDS; yields 4%
• 2ml beta -Mercaptoethanol; yields 2%
• 20ml of 100% glycerol; yields 20%
• 1.36gTRIS base (FW=121.1); yields 112.5mM
• Bromophenol blue; yields 0.01%
• add distilled water till 100ml

In most cases, after dilution with equal volumes of Western Buffer A and Western Buffer B, the final concentrations of the loaded sample will be:

• 3% SDS
• 1% b -Mercaptoethanol
• 10% glycerol
• 62.5mM TRIS base
• 0.005% Bromophenol blue

Samples should be boiled for 5min after final dilution and then loaded.