Description:

LB Broth recommended for the cultivation and maintenance of recombinant strains of Escherichia coli for genetic and molecular biology studies; may be used for routine cultivation and estimation of not particularly fastidious microorganisms.

Composition**
Ingredients Gms / Litre
Tryptone 10.000
Yeast extract 5.000
Sodium chloride 10.000
Final pH ( at 25°C) 7.5±0.2
**Formula adjusted, standardized to suit performance parameters

Directions:
Suspend 25 grams in 1000 ml purified / distilled water. Heat if necessary to dissolve the medium completely. Dispense
in tubes or flasks as desired. Sterilize by autoclaving at 15 lbs pressure (121°C) for 15 minutes.
Principle And Interpretation
Luria Bertani Broth, Miller is slightly different with double amount of sodium chloride as compared to original media
described by Lennox (4) for cultivation and maintenance of recombinant strains of Escherichia coli (1). The media is
nutritionally rich for the growth of pure cultures of recombinant strains. Strains derived from Escherichia coli K12 are
deficient in Vitamin B synthesis which are further modified by specific mutation to create auxotrophic strains and are
therefore unable to grow on nutritionally deficient media.
Tryptone provides peptides while Vitamin B complex is provided by yeast extract. Sodium chloride provides sodium ions
for membrane transport and also maintains the osmotic equilibrium of the medium.
Intended

Use:
Luria Bertani Broth recommended for the cultivation and maintenance of recombinant strains of Escherichia coli for genetic and molecular biology studies; may be used for routine cultivation and estimation of not particularly fastidious microorganisms.