L B AGAR (Lennox)

LB Agar (Lennox) is a nutritionally rich medium developed by Lennox for the growth and maintenance of pure cultures of recombinant strains of E. coli used in molecular microbiology procedures. These strains are generally derived from E. coli K12, which are unable to produce vitamin B, so this media is formulated to enhance the growth of nutritionally demanding microorganisms. This strain of E. coli has been further modified through specific mutation to create an auxotrophic strain that is not capable of growth on nutritionally deficient media.
LB Agar (Lennox) has a different sodium chloride level than other media such as Luria Agar (Miller LB Agar) or Luria Agar (Miller Modification). This allows to select the optimum salt concentration of the medium for a specific strain.

for propagation and maintenance of E.coli