SOB: 2% Vegetable peptone (or Tryptone) 0.5% Yeast extract 10 mM NaCl 2.5 mM KCl 10 mM MgCl2 10 mM MgSO40.17 M NaCl LB agar: 1% Tryptone 0.5% Yeast Extract 1.5% Agar