What is FLAG-Tag
The FLAG octapeptide is a polypeptide protein tag that is fused to a recombinant protein. This tag has very high specificity as it is an artificial antigen to which extremely specific monoclonal antibodies are produced so proteins can be purified using techniques including affinity chromatography.
The FLAG-Tag is also used for protein localisation and recombinant protein isolation. Due to its mild purification procedure, the FLAG-Tag can also be used for isolating protein complexes consisting of multiple subunits.
FLAG-Tag structure
The FLAG-Tag, also known as DYKDDDDK-tag, has been in use for over 20 years, and as its alternative name suggests the tag consists of an amino acid sequence made from aspartic acid, lysine and tyrosine, bringing the total size of the tag to 1012.9 dalton or roughly 1 kDa.
The Flag-Tag can be added either to the N-terminus or the C-terminus of a protein or as a tandem formation, meaning multiple Flag-Tags can be used right next to each other .
A modified version of this tandem formation is even more frequently used today. This altered sequence is DYKDHDG-DYKDHDI-DYKDDDDK.
FLAG-Tag Polyclonal antibodies
FLAG-Tag Monoclonal antibodies
