Epitope tags have application in the labeling, isolation and detection of proteins using immunoblotting, Immunoprecipitation and immunostaining techniques. Epitope tags can be used, by affinity chromatography, to separate recombinant, overexpressed protein from wild-type protein expressed by the host organism. Due its small size the protein’s biochemical properties seem not to be affected by the tag protein. FLAG-tag, or FLAG octapeptide, a polypeptide consisting of eight amino acids (DYKDDDDK) can be added to a protein using recombinant DNA technology; therefore, the tag can be detected with the fused protein in many different assays that require recognition by an antibody.