HA tag (YPYDVPDYA) derived from the 98-106 amino acid of human influenza hemagglutinin protein, which has little influence on the spatial structure of exogenous proteins and is easy to be fused into the N-terminal or C-terminal of target proteins, so it is often used for expression of fusion proteins. Anti-HA Affinity Beads consists of 90µm beads of 4% agarose, to which anti-HA antibody has been coupled as affinity ligand. Anti-HA Affinity Beads can be used to purify HA tag fusion proteins expressed in prokaryotes, yeast or mammalian cells in one step or for immunoprecipitation.