Luria-Bertani Medium (aka L-Broth or LB Medium). (Bertani says LB really stands for lysogeny broth.) LB is a standard growth medium for a variety of bacteria and conditions.
- 10 g Bacto-tryptone
- 5 g yeast extract
- 10 g NaCl
See also: Silver: LB Liquid
Note: There are two formulations of LB, Miller and Lennox, that differ in the amount of NaCl. Lennox has less salt, only 5 g/L. The Qiagen miniprep kit recommends LB with 10 g NaCl for highest plasmid yields.
- Mix dry ingredients and add distilled water up to 1 Liter
- Pour into 2 L flask (or greater)
- Autoclave (liquid cycle)
- 250°F, 22psi, 30 minutes
Notes: We do not pH medium when we make it on the fly. However, if it is really important, pH the medium to 7.0 with 5M NaOH (~200µL). We usually obtain this from the kitchen.
J. Sambrook, D.W. Russell, Molecular Cloning: A Laboratory Manual (Cold Spring Harbor Laboratory Press, New York, ed. 3, 2001) pg. A2.2