Western Blot

Western Blotting could be used to follow protein phosphorylation. An antibody that binds to all the isoforms of a poly-phosphorylated protein will show a 'beads-on-a-string" look on a 2D gel. Western Blotting is also useful for identifying known and unknown proteins in complexes brought down by co-immunoprecipitation. Once proteins of interest are located on a Western blot, corresponding spots can be cut from a duplicate Coomassie blue-stained gel and identified by MS.