Jan 06, 2023
Version 2
Lysogeny Broth (LB) medium V.2
- Andreas Sagen1
- 1University of Oslo
Protocol Citation: Andreas Sagen 2023. Lysogeny Broth (LB) medium. protocols.io https://dx.doi.org/10.17504/protocols.io.ewov1o262lr2/v2Version created by Andreas Sagen
License: This is an open access protocol distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Protocol status: Working
We use this protocol and it's working
Created: January 06, 2023
Last Modified: January 06, 2023
Protocol Integer ID: 74863
Keywords: LB, bacteria, Lennox broth, E. coli, Escherichia coli, medium lysogeny broth, lysogeny broth, several common formulations of lb, formula of the lb medium, abbreviation lb, lennox broth, helpful for bacterial growth, broth, luria broth, lb medium, bacterial growth, essential amino acid, lb, ingredient, essential amino acids such as peptide, similar composition of ingredient, magnesium, compound, vitamin, growing bacteria, yeast extract, peptide, sodium chloride, peptone, plethora of organic compound, mineral, osmotic balance, bertani medium, sodium, nitrogen, sodium ions for transport, several common formulation, bacteria, organic compound, yeast, casein peptone
Abstract
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.
Guidelines
Follow step by step, unless stated otherwise. Equipment needed should be standard to a microbiology lab.
Materials
Analytical scale, autoclave, bottle, weight vessel, LAF bench
Protocol materials
TryptoneMerck Millipore (EMD Millipore)Catalog #T9410
Yeast ExtractMerck MilliporeSigma (Sigma-Aldrich)Catalog #Y0875
Sodium chlorideMerck MilliporeSigma (Sigma-Aldrich)Catalog #S9625
AgarMerck MilliporeSigma (Sigma-Aldrich)Catalog #A1296
Troubleshooting
Safety warnings
When removing autoclaved components, be sure to take care as this can be very hot. If using antibiotics, use sufficient PPE to protect yourself, as some can be toxic to humans.
Before start
Prepare glassware by cleaning it, and ensure that scale is sufficiently calibrated
500 mL LB-Lennox (broth) medium
All compounds are measured using a high precision analytical scale from powdered compounds. Each compound is measured to within 1% of the target weight. All compounds are mixed in a Duran bottle
Fill the bottle with 400 mL double-distilled water
Measure 5000 mg Tryptone, 2500 mg Yeast extract and 2500 mg Sodium chloride
Powdered compounds:
TryptoneMerck Millipore (EMD Millipore)Catalog #T9410
Yeast ExtractMerck MilliporeSigma (Sigma-Aldrich)Catalog #Y0875
Sodium chlorideMerck MilliporeSigma (Sigma-Aldrich)Catalog #S9625
Add powdered solids into bottle, and use a magnetic mixer with a stir bar to mix for 00:05:00
5m
Adjust pH while mixing to 6.7 using concentrated sodium hydroxide
Add distilled water to a total of 500 mL
Autoclave liquid at 121 °C for 00:15:00
Note
Cool to 50°C and supplement with antibiotics as appropriate
15m
500 mL LB-Lennox (agar) medium
20m
All compounds are measured using a high precision analytical scale from powdered compounds. Each compound is measured to within 1% of the target weight. All compounds are mixed in a Duran bottle
Fill the bottle with 400 mL double-distilled water
Measure 5000 mg Tryptone, 2500 mg Yeast extract, 2500 mg Sodium chloride and 7500 mg agar
Powdered compounds:
TryptoneMerck Millipore (EMD Millipore)Catalog #T9410
Yeast ExtractMerck MilliporeSigma (Sigma-Aldrich)Catalog #Y0875
Sodium chlorideMerck MilliporeSigma (Sigma-Aldrich)Catalog #S9625
AgarMerck MilliporeSigma (Sigma-Aldrich)Catalog #A1296
Add powdered solids into bottle, and use a magnetic mixer with a stir bar to mix for 00:05:00
5m
Adjust pH while mixing to 6.7 using concentrated sodium hydroxide
Add distilled water to a total of 500 mL
Autoclave liquid at 121 °C for 00:15:00
Note
Cool to 50°C and supplement with antibiotics as appropriate
Agar can be stored, then reheated to 50°C to be poured
15m