LB Broth, also known as, LB medium, Lysogeny broth, Luria broth, or Luria-Bertani medium, is a commonly used nutritionally rich medium for culturing bacteria. First described in 1951 by Giuseppe Bertani, a 1-liter medium consists of 10 grams of tryptone, 5 grams of yeast extract, and 10 grams of sodium chloride. For salt-sensitive applications, the Lennox modification only includes 5 grams of salt per liter. LB medium is widely-used in molecular biology for growing recombinant E. coli for use in plasmid purification and protein expression. For convenience, commercial LB powder and liquid formulations are available, already mixed and ready-to-use.