Wittrup: E. coli Media

LB Media [see also LB]

Liquid, 1000 mL

• 10g Bacto tryptone
• 5g Bacto yeast extract
• 10g NaCl

pH to 7.5 with NaOH (optional?) Add ddH2O to final volume. Filter sterilize, or autoclave. Add antibiotic if selective media is desired (perhaps 100 mg/L amp), but do not add until cooled to below 50 oC (touchable by bare hand)

Plates, 1000 mL

• Ingredients as above (still save antibiotic for last)
• 15-18g agar
• Autoclave. Add antibiotic if selective media is desired, but do not add until cooled to below 50 oC (touchable by bare hand)

Ampicillin [see also Ampicillin]

• Stock: 25 mg/mL of sodium salt of ampicillin (amp) in water.
• Filter sterilize and store in aliquots of 4 mL at -20 oC
• Working concentration = 35-50 mg/L for liquid media. Often 100 mg/L for plates.

SOC Media [see also SOC]

100 mL

• 2.0g 2% Bactotryptone
• 0.5g 0.5% Yeast extract
• 10 mM NaCl (0.2 mL 5 M)
• 10 mM MgCl2 (1.0 mL 1 M)
• 10 mM MgSO4 (1.0 mL 1 M)
• 20 mM Dextrose (D-glucose) (0.36 g)

Add ddH20 to final volume. Filter sterilize, or autoclave.