Molecular biology · Agar
LB Agar – lysogeny agar for E. coli
LB Agar is the solid form of lysogeny broth. It is used for the propagation and maintenance of E. coli strains and, with added antibiotics, for the selection of transformants in molecular biology.
- Propagation and maintenance of E. coli
- Selection of transformants with antibiotics
- Blue-white screening with X-gal and IPTG
How LB Agar works
Tryptone and yeast extract support rapid growth, and agar solidifies the medium. Antibiotics, X-gal or IPTG are added to the cooled medium before the plates are poured.
Typical colony appearance
| Organism | Colonies |
| Escherichia coli | Grey-white colonies |
Technical data
| Preparation | 36 g/L; boil to dissolve, dispense, autoclave 121 °C 15 min |
| Final pH | 7.0 ± 0.2 |
| Incubation | 36 ± 1 °C, 18–24 h |
| Storage | Sealed, cool, dry and dark place |
| Shelf life | 3 years |
Applications and practical notes
Molecular biology and research laboratories use defined, rich media to grow recombinant E. coli, to produce plasmids and proteins, and to cultivate special organisms such as cyanobacteria. Typical applications include:
- Growth of recombinant E. coli strains
- Plasmid and protein production
- Culture of cyanobacteria and algae
- Research and teaching laboratories
Working with LB Agar: Add antibiotics at about 50 °C and store the plates in the dark at 2–8 °C for no longer than a few weeks.
Good practice with dehydrated media: keep the bottle tightly closed in a cool, dry place, weigh the powder quickly to avoid moisture uptake, and use fresh distilled or deionised water. Check the pH of each new batch after preparation and before use, and label prepared media with the date. Performance of each lot can be verified with reference strains according to ISO 11133, the standard for the preparation, production, storage and performance testing of culture media.
About general-purpose media: general-purpose media are not tied to one reference method. They are used in every laboratory for cultivation, revival of reference strains, purity checks and as bases for enriched and test media. Their performance is verified with reference strains according to ISO 11133, and media for susceptibility testing follow the requirements of EUCAST and CLSI. COLO.Science offers general media, enriched bases, supplements and QC strains from one source.
Complete sets from one supplier: COLO.Science supplies culture media, supplements, rapid tests, identification kits and QC strains as complete sets for the method you follow. Send us your sample types and standards, and we will prepare an offer with the matching products and documentation.
LB Agar is supplied by COLO.Science in the pack sizes listed under Ordering information. For larger quantities, regular deliveries or method-specific sets that include LB Agar, please send us a request. With every delivery of LB Agar you receive the lot number and expiry date, and on request we send the available documentation for LB Agar.
Where LB Agar fits in general microbiology
- Sample preparation – Peptone Water, Phosphate Buffer and other diluents
- Cultivation and revival – Nutrient, BHI and Columbia media
- Fastidious organisms – blood, chocolate and GC media with supplements
- Testing and identification – Mueller Hinton for susceptibility, CLED and chromogenic agar for urine, biochemical tests
See all general-purpose media in the Microbiology Catalogue →
Ordering information
| Product | COLO code | Pack |
|---|---|---|
| LB Agar | PRO7578 | 500 g |
Product notice: preparation, storage conditions and shelf life are given on the label. Technical data on this page are for orientation; the label and the lot documentation apply. B2B prices are quoted net, excluding VAT.
Sales and technical support
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Quotations and technical support for culture media and microbiology products across our international sales territory. B2B prices are net, excluding VAT.
COLO.SCIENCE | MICROBIOLOGY SUPPORT
Need the complete set for your method?
Send the sample type, target organism and the standard you follow. COLO.Science will put together the media, supplements, QC strains and confirmation tests for the whole procedure.
