LB Broth, Lennox

LB Broth, Lennox is used in molecular genetic studies in a laboratory setting. LB Broth, Lennox is not intended for use in the diagnosis of disease or other conditions in humans.

LB Broth formula is based on L Broth described by Lennox for growth and maintenance of E. coli strains used in molecular microbiology procedures. LB Broth is nutritionally rich, formulated for the isolation of pure recombinant strains. E. coli is grown to late log phase in LB Broth. Some plasmid vectors may replicate to high copy numbers without selective amplification. Some vectors may require selective amplification to reach high copy numbers. Chloramphenicol can be added to inhibit host synthesis and, as a result, prevent replication of the bacterial chromosome.

LB Broth contains ten times the sodium chloride level of Luria Broth, Miller and one half of that found in LB Broth, Miller. This permits the researcher to select the optimal salt concentration for a specific strain. If desired, the medium may be aseptically supplemented with glucose to prepare the complete medium described by Lennox.


Formula Liter
Enzymatic Digest of Casein 10 g
Yeast Extract 5 g
Sodium Chloride 5 g

Final pH: 7.3 ± 0.2 at 25°C
Formula may be adjusted and/or supplemented as required to meet performance specifications.


  1. Dissolve 20 g of the medium in one liter of purified water.
  2. Mix thoroughly.
  3. Autoclave at 121°C for 15 minutes.

Order Details

Product # Product Description
7290A LB Broth, Lennox, 500 g
7290T LB Broth, Lennox, 5 kg