IPTG overlay solution
12 ml required for each recombinant plaque analyzed. After autoclaving the 0.5x LB medium, supplement it with 1 M IPTG (2.38 g of IPTG in a final volume of 10 ml of sterile H2O) and 1 M MgSO4 (24.6 g of MgSO•7H2O in a final volume of 100 ml of sterile H2O) to bring their final concentrations to 5 and 10 mM, respectively. For each 150-mm agar plate, 12 ml of IPTG overlay solution is required.
