What are LB agar plates used for?

About LB agar plates Luria-Bertani (LB) agar plates are nutrient-rich plates used for growing bacteria on. They are commonly used during cloning experiments to amplify antibiotic-resistant, competent bacteria.

What is LB in biology lab?

Lysogeny broth (LB) is a nutritionally rich medium primarily used for the growth of bacteria.

Why is LB agar used to grow bacteria?

The flat, solid properties of LB agar allow the plating of bacterial cultures and generation of colonies. In the absence of antibiotics, LB agar is nutritionally rich, allowing the growth of most microorganisms.

What is LB nutrient agar?

Luria Bertani (LB) agar is a common nutrient agar for the general routine growth of bacteria and is not preferentially suited toward a particular microbe type. Miller’s LB agar is a variety of LB containing different proportions of the same components.

How long do LB AMP plates last?

The plates last longer and reduces the formation fo satellite colonies. They last about 3-4 months.

Why is the plate labeled on the bottom?

The lid of Petri dishes may contain any contamination that spreads on the media and grows with the sample microbes. We label the Petri dishes at the bottom part because lid may exchange with other Petri dishes creating confusion and inverted position makes it easy to read the labeling of Petriplates.

What does LB stand for?

Roman libra The libra (Latin for “scales / balance”) is an ancient Roman unit of mass that was equivalent to approximately 328.9 grams. It was divided into 12 unciae (singular: uncia), or ounces. The libra is the origin of the abbreviation for pound, “lb”.

What is the difference between LB agar and LB broth?

Agar is a polysaccharide isolated from a plant and is used for microbial cultures on solid media. LB broth is generally used for inoculum preparation or start cultures in suspension medium. The only difference between broth and agar media is that broths do not contain an agar component… Thank you.

What bacteria grows on LB agar?

Although originally developed for bacteriophage studies and Shigellagrowth, LB subsequently became the medium of choice for growth of Escherichia coli and other related enteric species. LB medium is a rich medium that is commonly used to culture members of the Enterobacteriaceae as well as for coliphage plaque assays.

How do you make a LB amp plate?


  1. 500 mL makes about one sleeve of petri dishes.
  2. Add 25g LB Broth per Liter to an appropriately sized beaker.
  3. Add Water and Stir until clumps are gone.
  4. Add 15 g Agar per Liter , this will not dissolve.
  5. Transfer to a erlenmeyer flask at least 2x the volume that you are making.

How long do LB agar plates last in fridge?

Beside the occurrence of contamination, leaving agar plates for 3 months at fridge, make them dry out and unsuitable for bacterial cultivation and isolation.

How are LB agar plates used to isolate bacteria?

LB agar plates are frequently used to isolate individual (clonal) colonies of bacteria carrying a specific plasmid. However, a liquid culture is capable of supporting a higher density of bacteria and is used to grow up sufficient numbers of bacteria necessary to isolate enough plasmid DNA for experimental use.

What is the purpose of lysogeny broth ( LB )?

Lysogeny broth (LB), a nutritionally rich medium, is primarily used for the growth of bacteria.

What are LB media used for in microbiology?

LB media formulations have been an industry standard for the cultivation of Escherichia coli as far back as the 1950s. These media have been widely used in molecular microbiology applications for the preparation of plasmid DNA and recombinant proteins.

What’s the difference between Ed La and LB agar?

For LB agar* add agar to a final concentration of 1.5%. Heat the mixture to boiling to dissolve agar and sterilize by autoclaving at 15 psi, from 121-124°C for 15 minutes. * Strictly speaking, LB agar should be call ed LA. LB Variations Variations of the LB recipe can be found in the literature and lab manuals.