SOB

A rich medium for cell growth

• 0.5% (w/v) yeast extract
• 2% (w/v) tryptone
• 10 mM NaCl
• 2.5 mM KCl
• 20 mM MgSO₄

Per liter:

• 5 g yeast extract
• 20 g tryptone
• 0.584 g NaCl
• 0.186 g KCl
• 2.4 g MgSO₄

• Some formulations of SOB use 10 mM MgCl₂ and 10 mM MgSO₄ instead of 20 mM MgSO₄.
• Adjust to pH 7.5 prior to use. This requires approximately 25 ml of 1M NaOH per liter.

SOC

If you need SOC, just add glucose to a final concentration of 10mM (3.603g in a litre). This is good recovery medium for the chemically competent cells transformation protocol.