Purification of GST-PP5 from BL-21 cells. Cells were grown to OD = 0.5 and IPTG-induced (0.1 mM) (lanes 1–4) and uninduced (lanes 5–8) cultures were left to stir for two hours at room temperature. Protein was extracted and purified using GST-spin columns. Lanes are representative of the elution process: total protein lysate (lanes 1 and 5), flow through washes (lanes 2–3 and 6–7) and GST-PP5 protein eluate (lanes 4 and 8).