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From 2013.igem.org

Labbook |	Protocols |	Materials |

SOB

The SOB medium is used for growth of bacteria in preparation of chemically competent cells.

Ingredients

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

For 1 L:

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

Adjust to pH 7.5 prior to use. This requires approximately 5 mL of 5M NaOH per liter.