Glutathione Sepharose High Performance consists of highly cross-linked 34 μm agarose beads to which glutathione has been immobilized. The resulting medium selectively retains GST-tagged recombinant proteins, allowing them to be purified from cellular contaminants in one-step. Small bead size provides separated peaks containing concentrated material. Several formats are offered, including lab packs of 25 and 100 ml, as well as pre-packed GSTrap™ HP 1- and 5-ml columns. The columns are simple to use either with just a syringe, a simple pump, or on a chromatographic system.