Lysogeny broth (LB) is a nutritionally rich medium which is primarily used for the growth of bacteria[1]. The initialism is also commonly, albeit incorrectly, taken to mean Luria broth , Lennox broth , or Luria-Bertani medium . According to its creator Giuseppe Bertani, the abbreviation LB was actually intended to stand for lysogeny broth . The formula of the LB medium was

published in 1951 in the first paper of Bertani on lysogeny[2]. There are several common formulations of LB . Although they are different, they generally share a somewhat similar composition of ingredients used to promote growth, including the following: Peptides and casein peptones, Vitamins (including B vitamins), Trace elements (e.g. nitrogen, sulfur, magnesium) and Minerals.

Sodium ions for transport and osmotic balance are provided by sodium chloride (NaCl). Tryptone is used to provide essential amino acids such as peptides and peptones to the growing bacteria, while the yeast extract is used to provide a plethora of organic compounds helpful for bacterial growth. These compounds include vitamins and certain trace elements.

Prepare glassware by cleaning it, and ensure that scale is sufficiently calibrated