Recombinant protein purification with affinity chromatography is a highly specific method. Most researchers utilize a HIS-tag for inexpensive recombinant protein purification. Histidine containing fusion proteins can be purified with our HIS-Select™ family of products with high selectivity. The FLAG® system is designed for highly sensitive detection of recombinant protein. Protein purification and detection tools for many other fusion proteins are also available. For example, Sigma offers agarose-based affinity resins for purification of c-Myc, HA and MBP (Maltose Binding Protein) fusion proteins.