Glutathione S transferases (GSTs) are a family of enzymes that play an important role in detoxification by catalyzing the conjugation of many hydrophobic and electrophilic compounds with reduced glutathione. GST proteins can be purified by immobilized glutathione affinity chromatography. Many recombinant proteins have been engineered with GST tags to facilitate the detection, isolation and purification of these proteins. Monoclonal antibody reacting specifically with GST may be useful in various immunotechnique, to identify the expression of a GST fusion protein in bacteria, bacterial lysates or cells and tissues transfected with a GST fusion protein expressing vectors.