LB-Broth Lennox

LB-Broth Low Salt, Lennox L Broth

LB Broth Lennox is a nutritionally rich medium originally developed for growth and maintenance of recombinant E. coli strains. E. coli is grown to late log phase in LB Broth. These strains are generally derived from E. coli K12 which are deficient in B vitamin production. K12 has been ultimately modified by specific mutation into an auxothropic strain not capable of growth on nutritionally deficient medium. All nutritional requirements of E. coli strains are provided by LB Broth. Peptides and amino acids are abundantly present in Tryptone. Yeast extract is a rich source of amino acids, vitamins, nucleotides and carbohydrates. These nutritional elements in LB media, which otherwise the cell would have to synthesize, support a luxurious growth of E. coli cells.

Sodium ions for transport and osmotic balance are provided by Sodium chloride. The concentration of NaCl in LB Lennox is half the concentration of the LB Miller Broth formulation and ten times the concentration of LB Luria Broth formulation. These variations in Sodium chloride content make it possible to select the optimal salt concentration for a specific strain.

Lennox, E.S., Transuction of linked genetic characters of the host by bacteripphage P1, 1, 190-206, (1955). Assubel, F.M., R. Brent, R.E. Kingston, D.D. Moore, J.G. Seidman, J.A. Smith and K. Struhl, Current protocols in molecular biology, vol. 1, Current Protocols, New York, (1994).

Suspend 20 gram powdered medium in 1 litre distilled water

Store dry at room temperature