The FLAG™ tag (peptide sequence DYKDDDDK) is a short, hydrophilic protein tag commonly used in conjunction with antibodies in protein pull-downs to study protein–protein interactions. The FLAG tag may be inserted at the N terminus, the N terminus preceded by a methionine residue, the C terminus, or internal positions of the target protein. Because of its hydrophilic nature, the FLAG tag is commonly found on the surface of a fusion protein, which makes it more available as an epitope for binding to antibodies.
In addition, the high hydrophilicity and small size of the FLAG tag tend to interfere less with protein expression, proteolytic maturation, antigenicity, and function. FLAG tags are also easily removed by enterokinase (EK).
Quality Invitrogen antibodies specific to the FLAG tag are available for a variety of research needs. We also offer fluorescent and enzyme-conjugated versions for your added convenience.