Tandem Affinity Purification

The Tandem Affinity Purification (TAP) method involves the fusion of the TAP tag to the C-terminus of the new protein. The TAP tag consists of calmodulin binding peptide (CBP) from the N-terminal, followed by tobacco etch virus protease (TEV protease) cleavage site and Protein A, which binds tightly to IgG. The relative order of the modules of the tag is important because Protein A needs to be at the extreme end of the fusion protein so that the entire complex can be retrieved using an IgG matrix.
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