LB Agar Miller
Also known as：LB Agar (Miller)
For the cultivation and maintenance of Escherichia coli and other recombinant strains, and for the selection of transformants in molecular biology applications.
- Category
- Dehydrated Culture Media
- Dissolve per litre
- 40 g
- Pack sizes
- 500 g · 5 kg · 25 kg
- Certifications
- ISO 22000
Data updated：2026-11-06
Overview
LB Agar Miller is the solid form of the LB Miller formulation, with agar as the solidifying agent, used for plating, single-colony isolation, and post-transformation screening of Escherichia coli. Combined with antibiotics it supports plasmid selection and blue-white screening, making it the standard choice for the plating stage of cloning workflows.
Principle
LB Agar, Miller is the solid form of the nutrient-rich medium widely used for the cultivation of Escherichia coli in molecular biology and recombinant DNA work.¹ Tryptone provides nitrogen, amino acids, and peptides, while yeast extract supplies B-complex vitamins, nucleotides, and additional nitrogen and carbon sources. Sodium chloride maintains the osmotic balance and provides sodium ions for membrane transport. The Miller formulation contains 10 g/L of sodium chloride, a higher concentration than the Lennox and Luria formulations.² The medium is routinely used for the isolation of single colonies, the maintenance of stock cultures, and, with the addition of an appropriate antibiotic, the selection of plasmid-bearing transformants.
Choosing between Miller, Lennox, and low-salt formulations
The LB formulations differ mainly in sodium chloride content. Miller carries the highest level and is the default for most standard E. coli workflows; Lennox carries less and suits electroporation or osmotically sensitive strains. STBIO offers several further LB variants — contact us if you need a specific salt level or raw-material specification.
Directions
Suspend 40 g of powder in 1 L of purified water. Heat with continuous stirring and bring to the boil for 1 minute. Sterilize by autoclaving at 121°C for 15 minutes. Cool to 45-50°C and, where required, aseptically add the selective antibiotic. Mix well and pour into sterile Petri plates. Test the finished medium for performance using stable, standard control cultures.
Cultural response
| Test organism | ATCC | Growth |
|---|---|---|
| Escherichia coli | 25922 | good-luxuriant |
| Escherichia coli | 8739 | good-luxuriant |
Product highlights
- Food-grade raw materials, produced in an ISO 22000 certified facility
- Manufactured to the standard formulation, 40 g per litre
- Performance verified against standard control strains before release (Escherichia coli, Escherichia coli)
- Available in 500 g / 5 kg / 25 kg, from laboratory to industrial scale
- COA, specification sheet, and technical data sheet available; samples on request
- Manufactured in Taiwan with reliable supply
Food grade versus laboratory grade
Most culture media suppliers use laboratory-grade raw materials, which are held to lower standards for heavy metal residues, microbial contamination control, and traceability. That is adequate for pure research but not for applications with stricter raw-material requirements. STBIO manufactures with food-grade raw materials throughout, in a facility certified to ISO 22000 food safety management.
- Food microbiology laboratories working to ISO 17025 or equivalent requirements
- Biotech manufacturers exporting fermentation products and needing full raw-material traceability
- Organisations with ESG or compliance audit requirements across their supply chain
- Companies sourcing both Halal and non-Halal products who need one consistent material grade
Frequently asked questions
01What is the difference between LB Broth Miller and Lennox?
The main difference is the sodium chloride level: Miller contains more than Lennox. Miller is the default for most standard E. coli workflows, while Lennox suits electroporation and osmotically sensitive strains.
02Which LB medium should I use for transformation?
For chemical (heat-shock) transformation, the recovery step normally uses LB Broth Miller or Lennox, incubating at 37 °C for 45–60 minutes before plating. For electroporation, the low-salt Lennox formulation is recommended to avoid arcing.
03How does LB Broth differ from Nutrient Broth?
Both are general-purpose liquid media but differ in composition. LB Broth combines tryptone, yeast extract, and sodium chloride and is optimised for E. coli and recombinant strains, making it the standard in molecular biology laboratories. Nutrient Broth is simpler and suits routine cultivation but is not tailored to recombinant work.
04How much powder per litre?
Use 40 g per litre of deionised water; preparation and sterilisation conditions are given on the specification sheet.
05Which organisms is it suitable for?
Gram-negative, Aerobes, E. coli, Escherichia coli. See the cultural response table and the specification sheet.
06Can it be used for food-grade applications?
Yes. It is made from food-grade raw materials in an ISO 22000 certified facility and is suitable for culturing starters for fermented products that are consumed directly.
07How is this product prepared?
Suspend 40 g of powder in 1 L of purified water. Heat with continuous stirring and bring to the boil for 1 minute. Sterilize by autoclaving at 121°C for 15 minutes. Cool to 45-50°C and, where required, aseptically add the selective antibiotic. Mix well and pour into sterile Petri plates. Test the finished medium for performance using stable, standard control cultures.
08Is there a Halal certified version of this product?
Yes. This is the standard version; a Halal certified version is also produced from food-grade raw materials with Halal documentation, for compliant sourcing in Malaysia, Indonesia, and the Middle East.
09How do I request a bulk quotation, and can you provide a COA?
Yes. This product is available in 500 g, 5 kg, 25 kg. Tell us your application and volume when requesting a quotation; we reply within one working day and can supply the COA, specification sheet, and technical data sheet.
Academic citation
Products from this range have been cited as the culture media source in a peer-reviewed study by a National Taiwan University research team:
Chan et al. (2024). Single-strain probiotics enhance growth, anti-pathogen immunity, and resistance to Nocardia seriolae in grey mullet (Mugil cephalus) via gut microbiota modulation. Animal Microbiome, 6, 67. Springer Nature.
Media attribution: Tryptone Soy Broth, MRS medium, LB broth, beef extract, peptone, yeast extract, agar (STBIO, New Taipei, Taiwan)
Read the full paperUsed in these applications
References
- 1. Bertani G., 1951. Studies on lysogenesis. I. The mode of phage liberation by lysogenic Escherichia coli. J. Bacteriol., 62:293-300.
- 2. Miller J. H., 1972. Experiments in Molecular Genetics, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York.