The HA tag is derived from amino acid residues 98–106 of the human influenza virus hemagglutinin protein (sequence: YPYDVPDYA), and is a widely used universal epitope tag. Due to its hydrophilic nature and extremely small size, the HA tag is typically exposed on the surface of fusion proteins, facilitating antibody recognition without affecting the biological function of the target protein. This mouse monoclonal antibody has been validated for Western Blot (WB), Immunocytochemistry/Immunofluorescence (ICC/IF), and ELISA, and can be used for target protein detection, cellular localization, and quantitative analysis.