LB Medium

Info

Used for growing E. coli.

Protocol

1. Using a balance weigh out the following and transfer to a 1 litre screwcap bottle:
   • 25g LB-Miller powder *or* 20g LB-Lennox powder *or* 15.5g LB-Luria powder
   • (15g agar if making solid medium for plates)
2. Half fill the bottle with water
3. Mix until all the additives are dissolved
4. Adjust to pH 7.0 using the pH meter and adding drops of NaOH or HCl.
5. Make up to 1 litre with water
6. Autoclave

Notes

If adding antibiotic, add after autoclaving.

25g of LB-Miller powder consists of:

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

20g of LB-Lennox powder consists of:

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

15.5g of LB-Luria powder consists of:

• 10g tryptone
• 5g yeast extract
• 0.5g NaCl