Lab July 13 2009

From 2009.igem.org

Prepare SOB media and plates, http://openwetware.org/wiki/SOB.


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.


created 500 ml of SOB .


We used 1.5 g agar in 100 mL SOB for our plates.


autoclaved 400 ml SOB and 100ml SOB+agar and poured 5 plates.


obtained DH5α stocks from Crystal in Dr. Nano's lab.


using sterile technique and a sterile loop, scraped cells from DH5α seed culture, then streaked 4 plates. (1st 2 plates were still a bit warm, so were damaged.)



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