Sample Induction Protocol (for reference only) 1. Inoculate a single colony from a freshly streaked plate into 5 ml of LB medium containing the appropriate antibiotic for the plasmid and host strain. 2. Incubate with shaking at 200 rpm at 37℃ overnight. 3. Inoculate 50 ml of LB medium containing the appropriate antibiotic with 0.5 ml of the overnight culture prepared in step 2(use the 500 ml triangular flask as the container would be better). 4. Incubate with shaking at 150 rpm at 37℃ until the OD 600 reaches 0.5-0.8. 5. (Optional)Pipet 1ml of the cultures into clean microcentrifuge tubes and place the tubes on ice until needed for gel analysis or storage at -20℃. These will serve as the non-induced control samples. 6. Add IPTG to a final concentration of 1 mM. Optimal time for induction of the target protein may vary from 2-16 hours, depending on the protein. 7. Incubate with shaking at 120 rpm at 37℃ for 3-4 hours. To determine the optimal time for induction of the target protein, it is recommended that a time course experiment be performed varying the induction from 2-16 hours. 8. Place the culture on ice for 10 minutes. Harvest cells by centrifugation at 5,000×g for 10 minutes at 4℃. 9. Remove the supernatant and store the cell pellet at -20℃ (storage at lower temperatures is also acceptable). IPTG Prepare a 1 M solution of IPTG (Isopropyl-β-D-thiogalactoside; Isopropyl-β-D-thiogalactopyranoside) by dissolving 2.38 g of IPTG in dd water and adjust the final volume to 10 ml. Filter sterilize before use.