SOB

Super Optimal Broth. For 1 L medium, mix the following components in a Schott bottle:

• 20 g Tryptone or Peptone
• 5 g Yeast extract
• 0.5 g NaCl
• 1 mL KCl 2.5 M

Autoclave, cool to room temperature and add:

• 5 ml of a sterile 2M MgCl2
• 5 mL of sterile 2M MgSO4

Alternatively, the Tryptone and Yeast Extract can be autoclaved and the rest of the components can be added from sterile stock solutions:

• 1 mL/L 250 g/L NaCl
• 1 mL/L 2.5 M KCl
• 5 ml/L of a sterile 2M MgCl2
• 5 mL/L of sterile 2M MgSO4