Lysogeny Broth (LB) is one of the most common liquid media for culturing bacteria. It is also referred to as Luria Broth or Luria-Bertani medium (both also abbreviated as LB). LB is a nutrient-rich medium that allows rapid and robust growth of bacteria. Oftentimes, the media will be supplemented with an antibiotic that allows selection of transformants carrying plasmids encoding resistance genes (see LB Amp and LB Kan).


Dissolve the following in 1L ddH2O:

  • 10g bacto-tryptone
  • 5g bacto-yeast extract
  • 10g NaCl (5g in some recipes)

Adjust to pH 7.0 with 1N NaOH

Autoclave at 121°C for 15-20 minutes

Store at 4°C or RT