Protein tags are protein or peptide sequences located either on the C- or N- terminal of the target protein, which facilitates one or several of the following characteristics: solubility, detection, purification, localization and expression. GST(Glutathione S-Transferase) is a widely used protein tag encoded by the Schistosoma japonicum. GST provides both an easily detectable tag and a simple purification process with little effect on the biological function of the protein of interest. Antibodies to GST are useful for checking protein expression both in plaques and on Western blots as well as for immunoaffinity purification of proteins expressed in cells. This antibody recognizes the GST-tag fused to either the amino- or carboxy-terminus of targeted proteins.