Berglund:BL21 Star cells

Preparation of CaCl2 (heat-shock) competent cells Grow culture to an OD600 between 0.4 and 0.6 place on ice for 15 minutes spin down cells at 4000xg resuspend gently in half volume of ice cold 50mM CaCl2 Let sit on ice for 30 min spin down resuspend gently in 1/20 volume of ice cold 50mM CaCl2 + 10% glycerol incubate at least 1 hr on ice transform 200µl directly or quick freeze in a dry ice/ethanol bath and store at -80C Transformation: add 1µl plasmid and heat shock for 45 seconds at 42 degrees in a water bath