SOB/SOC: Super Optimal Broth

For SOB:

1L	Final [ ]	Component
5 g	0.5%	yeast extract
20 g	2.0%	tryptone
0.5 g	10 mM	NaCl
0.186 g	2 mM	KCl
2.4 g	20 mM	MgSO4 (anhydrous)

Add 800 ml of dH₂O and dissolve components. Adjust to pH 7.5 prior to use with 1 M NaOH (approximately 25 ml). Add dH₂O to a final volume 1 L. Autoclave

For SOC (=SOB+glucose):
Make SOB, except add dH₂O to a final volume of 960 ml instead of 1 L. Autoclave. When solution has cooled to 50°C (cool enough to touch with bare hands for a few seconds), add 40 ml of sterile 10% (w/v) glucose. (That's a final concentration of 0.4% glucose.)

Generally when making stocks of SOC it is advisable to make up multiple 125 of 250ml bottles. This media is extremely rich and can contaminate easily (smaller volumes tend to be pulled from it repeatedly with pipettes, which increases the chances of contamination over time).

Note: Some recipes for SOB use 10 mM MgSO₄ and 10 mM MgCl.