SOB: Difference between revisions
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*2.4 g MgSO<sub>4</sub> | *2.4 g MgSO<sub>4</sub> | ||
''Note:'' Some formulations of SOB | ''Note:'' Some formulations of SOB use 10 mM MgCl<sub>2</sub> and 10 mM MgSO<sub>4</sub> instead of 20 mM MgSO<sub>4</sub>. | ||
SOB medium is also available dry premixed from Difco, 0443-17. | SOB medium is also available dry premixed from Difco, 0443-17. | ||
Revision as of 08:28, 9 May 2006
Summary
SOB Medium. Used in growing bacteria for preparing chemically competent cells
Ingredients
- 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
Note: Some formulations of SOB use 10 mM MgCl2 and 10 mM MgSO4 instead of 20 mM MgSO4.
SOB medium is also available dry premixed from Difco, 0443-17.
Adjust to pH 7.5 prior to use. This requires approximately 25 ml of 1M NaOH per liter.
Source
Adapted From:
F. Ausubel et al., Short Protocols in Molecular Biology (John Wiley & Sons, ed. 4, 1999) pg. A1-36
Trivia
SOB supposedly stands for super optimal broth.
