LB Agar - BioReagent

Cat. No.: L1528380

QUALITÉ & PURETÉ BioReagent, Suitable for microbiology

Storage

Protected from light,Room temperature

Shipped In

Normal

Application

1153

Vue d’ensemble

Suitable for the culture of Escherichia coli in molecular biology experiments.

Medium Formula (per liter):

Component	Content
Tryptone	10.0g
Yeast Extract	5.0g
Sodium Chloride	10.0g
Agar	15.0g
pH(25℃)	7.0±0.2

Instructions for use:

Weigh 40.0 g of this product into 1 L of distilled or deionized water, heat to dissolve, dispense, autoclave at 121 °C for 15 min, and set aside for later use.

Precautions:

1. Avoid direct contact with skin and eyes during operation. In case of accidental contact, rinse immediately with plenty of clean water.

2. This product is for laboratory research only and shall not be used for clinical diagnosis.

Spécifications

Spécifications et pureté

BioReagent, Suitable for microbiology

Stabilité et stockage

Store at room temperature long term (36 months).Store in the dark.

Conditions de stockage de stockage

Protected from light,Room temperature

Expédié en

Normal

Grade

BioReagent, Suitable for microbiology

Product Line

Produits biologiques

Propriétés chimiques et physiques

• Sensibilité: Light-sensitive

Application Protocols

The following protocols are provided as general, literature-based guidance for LB Agar; they are not item-specific specifications. Always adjust to your lab’s SOPs and the product’s CoA.

• A. LB Agar plate preparation

  1. Weigh the recommended mass of dehydrated LB Agar per liter (e.g., 35–40 g/L depending on formulation). 2) Add to DI water while stirring; heat to dissolve and briefly boil. 3) Autoclave at 121 °C for 15–20 min. 4) Cool to 50–55 °C; add sterile-filtered antibiotics/supplements. 5) Pour plates (20–25 mL/100 mm plate). 6) Let set; dry as needed; store inverted at 2–8 °C.

• B. Antibiotic supplementation (examples; general)

  • Ampicillin: 50–100 µg/mL final; add from 1000× stock (filter-sterilized) at 50–55 °C.
  • Kanamycin: 25–50 µg/mL final; similarly added.
  • X‑gal/IPTG for blue/white screening as required (avoid light; add post-sterilization).

• C. Top agar overlays for phage/plating

  • Prepare a separate soft agar (e.g., 0.6–0.8% agar) LB; keep molten at ~45 °C. Mix with cells/phage and overlay onto LB agar base.

• D. Colony handling

  • Incubate plates inverted to reduce condensation (commonly 30–37 °C). Pick single colonies with sterile tools; streak for isolation as needed.

For exact concentrations and preparation instructions for this SKU, consult the CoA/Spec Sheet.

Biological Roles

LB Agar is a culture medium, not a biomolecule with a specific biological role. Its components provide nutrients and a solid support that enable bacterial growth (literature, general):

• Nutritional profile
  • Tryptone supplies peptides and amino acids for anabolic pathways and energy metabolism.
  • Yeast extract contributes vitamins (B-complex), nucleotides, and trace elements that support robust growth of many heterotrophic bacteria.
  • NaCl maintains osmotic balance, influencing cell envelope integrity and transport.
• Physical scaffold
  • Agar forms a thermo-reversible gel that is generally not metabolized by common laboratory strains of E. coli, providing a stable, non-nutritive matrix for colony formation and phenotypic selection.
• Use in molecular biology workflows
  • Facilitates selection of transformants when combined with antibiotics and indicators.
  • Supports phenotypic assays (e.g., motility in semi-solid agar, metabolic reporters on supplemented plates).

Limitations (general):

• Poor buffering capacity; pH can drift during vigorous growth.
• Not suitable for fastidious organisms without additional supplements.

Item-specific biological performance characteristics (e.g., growth promotion tests, gel strength) are not provided here and should be obtained from the CoA/Spec Sheet.

Buffer Applications

LB Agar is not a buffer and provides minimal buffering capacity. Consequently, it is not typically chosen to control pH in biochemical assays. Practical notes (literature, general):

• Typical LB formulations have an initial pH around neutral (~7.0–7.5), but the pH can change substantially during bacterial growth due to metabolism.
• For applications requiring pH stability on plates:
  • Supplement LB with a buffer system (e.g., 50 mM MOPS for near-neutral pH; phosphate buffers for pH 6–8), or use a defined buffered medium.
  • Prepare the buffer in the aqueous phase prior to sterilization; add heat-labile components after autoclaving when cooled to ~50–55 °C.
• Electrophoresis/cell culture: LB Agar is not used as an electrophoresis buffer or as a cell culture buffer; see Tris, TAE/TBE, PBS, HEPES, MOPS, etc., for those applications.

Item-specific buffering details are not provided; consult the CoA/Spec Sheet if a buffered LB variant is offered.

Green Alternatives

While LB Agar itself is widely used and generally benign, sustainable practice focuses on preparation and waste handling rather than replacing the medium. Consider the following (general, literature-based):

• Resource considerations
  • Agar is derived from marine algae (renewable biomaterial). Choose suppliers with responsible sourcing.
  • Dehydrated media minimize transport of water, reducing shipping weight and packaging compared to ready-to-pour formats.
• Energy and water usage
  • Optimize autoclave loads to full capacity to reduce per-batch energy and water consumption.
  • Use appropriate cycle lengths (validated 121 °C, 15–20 min) and avoid over-sterilization.
• Waste minimization
  • Prepare only the volume needed; store excess agar at 45–55 °C short-term if more plates are needed within hours to avoid remelting cycles.
  • Solid biological waste should be autoclaved and then disposed of per institutional guidelines; consider compostable/bio-based plate materials where compatible.
• Alternatives and trade-offs (general)
  • Ready-made sterile plates reduce in-lab energy/water use but increase shipping volume and single-use plastics.
  • Buffered or minimal media (e.g., M9 + agar) can reduce nutrient load for specific applications but may not support rapid growth.

Table (general comparison)

• Dehydrated LB Agar (this product): On-demand prep; lower shipping mass; requires autoclave energy.
• Pre-poured plates: Convenience; higher packaging waste; increased shipping mass.

Pharmaceutical Uses

No therapeutic or clinical claims. In pharmaceutical and biomanufacturing laboratories, LB Agar is used in support and quality-related activities (general, literature):

• Environmental monitoring and bioburden assessments after suitable qualification, where a rich, non-selective agar is acceptable for total aerobic count of non-fastidious organisms (method-specific; alternatives like TSA are common).
• Strain maintenance and cloning of production-related research strains (e.g., plasmid constructs) used in upstream development.
• Colony isolation and characterization during genetic manipulation workflows.

Regulatory considerations:

• For GMP use, media require lot-specific qualification (growth promotion testing, pH, gel strength) and documented traceability. Item-specific compliance status and test results: Not specified for this item; refer to CoA/Spec Sheet.
• End users remain responsible for ensuring suitability for intended use and for following compendial methods (USP/EP/JP) where applicable.

This product is designated “For research use only” per Product Data and is not marketed for diagnostic procedures or as a finished medical device.

Physical Properties

Because LB Agar is a dehydrated, multi-component medium, single-molecule physical constants do not apply. The following are typical, literature-based properties of LB agar media and agar gels (general guidance; not item-specific specifications):

• Physical state/appearance: Typically a free-flowing, beige to light tan powder; forms clear to slightly opalescent, firm gels after sterilization and cooling (literature, general). Item-specific appearance: Not specified for this item; refer to CoA/Spec Sheet.
• Solubility: Water-soluble blend prior to gelation; agar component hydrates upon heating to boiling; forms gels in water upon cooling (literature, general).
• Gelation behavior (from agar; literature):
  • Melting temperature ~85–90 °C; gelation (setting) ~32–40 °C, depending on concentration and impurities.
  • Typical plate firmness achieved at ~1.5% agar (15 g/L).
• pH (final, at 25 °C): LB media are commonly adjusted near pH ~7.0–7.5 depending on formulation (Miller, Lennox, Luria variants; literature). Item-specific pH: Not specified for this item; refer to CoA/Spec Sheet.
• Density/refractive index/logP: Not applicable to a solid mixture/aqueous gel.
• Thermal processing: Commonly sterilized by autoclaving at 121 °C for 15–20 min (literature, general). For heat-labile additives (e.g., antibiotics), cool to ~50–55 °C before addition.

Always follow the product’s CoA/specification for exact preparation, pH, and recommended use concentrations for this SKU.

Quality and Grades

• Item-specific grade: BioReagent (per Product Data). This denotes suitability for biological and microbiological laboratory procedures, with manufacturing controls aimed at reproducibility and low bioburden in the dehydrated product.
• What BioReagent implies (general context):
  • Sourced components (tryptone, yeast extract, agar, salts) are produced under controls appropriate for experimental biology. While not equivalent to clinical/diagnostic grade, the blend targets consistent microbial growth performance.
  • Typical QC for such media may include growth-promoting performance tests with reference strains, pH after preparation, and gel strength (literature, general). Item-specific QC metrics: Not specified for this item; refer to CoA/Spec Sheet.
• Stabilizers/additives: None typically required beyond the core components; antibiotics/selective agents are added by the end user as needed post-sterilization. Item-specific stabilizer info: Not specified for this item; refer to CoA/Spec Sheet.
• Appearance and performance tolerances: Not specified for this item; refer to CoA/Spec Sheet.
• Storage and shipping for this SKU:
  • Storage: Room temperature (per Product Data). Protect from moisture.
  • Shipped: Normal (per Product Data).

Note: For regulatory-sensitive applications (e.g., GMP microbiology), verify that the specific lot’s CoA/performance data meet internal acceptance criteria before use.

Reaction and Applications

LB Agar is not a reagent for organic reactions; it is a microbiological medium. Key laboratory applications (literature, general):

• Routine culture and maintenance of bacteria, especially Escherichia coli, on solid surfaces for colony isolation, counting, and selection.
• Plasmid selection and cloning when supplemented with appropriate antibiotics (e.g., ampicillin, kanamycin) and, where applicable, chromogenic substrates (e.g., X-gal) for blue/white screening.
• Phage work (with soft/top agar overlays) for plaque assays and lysate preparations.
• Transformation recovery plating and titering of libraries.
• Storage of strains as streaked master plates at 2–8 °C for short-term maintenance (days–weeks), acknowledging reduced viability over time.

Practical tips (general):

• Dissolve powder thoroughly in water with heating; bring to a brief boil to hydrate agar fully before sterilization.
• Autoclave at 121 °C for 15–20 min. Cool to ~50–55 °C before adding heat-sensitive supplements; mix gently to avoid bubbles.
• Pour plates on a level, sterile surface. Allow to solidify, then dry plates (e.g., 15–30 min at room temperature) before storage inverted at 2–8 °C in sealed bags to minimize desiccation.

Item-specific recommended mass per liter, target pH, and gel strength are not provided here; consult the CoA/Spec Sheet for this SKU.

Reaction Conditions

Interpreted as preparation and use conditions for the medium (general, literature-based; not item-specific specifications):

• Typical LB Agar formulation (example):
  • LB Miller plates: 10 g tryptone, 5 g yeast extract, 10 g NaCl, 15 g agar per liter of water (40 g/L total). LB Lennox uses 5 g/L NaCl (35 g/L total). Check your SKU’s label/CoA for the intended formulation.
• Preparation
  • Disperse powder in cold/room-temp water with stirring; heat to boiling to fully dissolve agar.
  • Sterilize by autoclaving at 121 °C for 15–20 minutes.
  • Cool to 50–55 °C, add sterile-filtered heat-labile additives (antibiotics, supplements), mix gently.
  • Pour ~20–25 mL per standard 90–100 mm plate; allow to set at room temperature on a level surface.
• Storage of prepared media
  • Plates: Invert and store in sealed sleeves/bags at 2–8 °C; use within 2–4 weeks for best performance (general guidance).
  • Broth (without agar): Use promptly or store at 2–8 °C for a short period to minimize contamination risk.
• Expected outcomes (general):
  • E. coli colonies visible within 12–18 h at 37 °C; slower at lower temperatures or for auxotrophs.

Item-specific reconstitution mass-per-liter, target pH, and QC acceptance criteria: Not specified for this item; refer to CoA/Spec Sheet.

Safety and Handling

• GHS classification, signal word, hazard statements, and pictograms: Not specified for this item; refer to SDS.
• General laboratory precautions (good practice for dehydrated media):
  • Avoid inhalation of dust; handle powders in a fume hood or with local exhaust when weighing. Wear lab coat, safety glasses, and appropriate gloves.
  • Prevent microbial contamination during preparation; sterilize by autoclaving, use aseptic technique, and keep prepared plates/broth closed.
  • After use, media containing microbial growth should be treated as biohazardous waste; autoclave prior to disposal in accordance with institutional biosafety procedures.
• Incompatibilities and special risks:
  • No specific chemical reactivity hazards expected under normal use. Avoid contact with strong oxidizers and strong acids/bases that can degrade medium constituents (general guidance).
  • Thermal burns/steam hazards during autoclaving and when pouring plates; wear heat-resistant gloves and face/eye protection.
  • Dehydrated media are hygroscopic; moisture uptake causes caking and can alter performance; keep container tightly closed.
• First-aid overview (general):
  • Inhalation: Move to fresh air; seek medical advice if irritation persists.
  • Skin/eye contact: Rinse with water; remove contaminated clothing; seek medical attention if irritation continues.
  • Ingestion: Rinse mouth; seek medical advice.

Always consult the product-specific SDS for authoritative safety information and local biosafety policies for handling microbial cultures.

Solvent Selection

This product is a dehydrated microbiological medium; it is not used as a solvent. The relevant “solvent” for preparation is purified water.

• Water quality (general guidance):
  • Use deionized/distilled water meeting microbiology-grade standards (e.g., ASTM Type II or better). High ionic contaminants or organics can influence growth and gel clarity.
• Miscibility and polarity: The medium is designed for aqueous preparation only. Organic solvents are neither needed nor recommended for reconstitution.
• Practical selection tips:
  • For routine cloning/propagation, standard LB agar is prepared in water, sterilized by autoclaving, cooled to ~50–55 °C, then supplemented with selective agents as required.
  • If buffering capacity is needed, consider preparing LB with an added buffer (e.g., MOPS or phosphate; literature, general) or use a buffered medium alternative.
• Comparison (literature, general):
  • LB Agar vs. nutrient agar: LB is richer for enteric bacteria (e.g., E. coli) due to tryptone/yeast extract composition.
  • LB Lennox vs. LB Miller: Differ mainly in NaCl concentration (5 g/L vs. 10 g/L, respectively). Check item-specific instructions before preparation. Item-specific formulation: Not specified for this item; refer to CoA/Spec Sheet.

Storage and Reconstitution

• Storage conditions (item-specific): Room temperature (per Product Data). Keep container tightly closed and protected from humidity. Shipped under normal conditions.
• Shelf life: Not specified for this item; refer to CoA/Spec Sheet.
• Reconstitution/preparation (general, literature-based):
  • Mass per liter: Follow the label/CoA. Typical LB Agar usage is ~35–40 g per liter depending on formulation (e.g., Lennox vs. Miller). Item-specific mass-per-L: Not specified for this item; refer to CoA/Spec Sheet.
  • Dissolve powder in purified water with heating; bring to a brief boil to hydrate agar. Autoclave at 121 °C for 15–20 minutes.
  • Cool to 50–55 °C before adding sterile-filtered, heat-labile supplements (antibiotics, indicators). Mix gently to avoid bubbles and stratification.
  • Pour plates on a clean, level, sterile surface. Allow to solidify and dry briefly before bagging.
• Storage of prepared media (general):
  • Plates: Store inverted in sealed sleeves or bags at 2–8 °C. Minimize exposure to light and desiccation. Use within a few weeks for optimal performance.
  • Broth (no agar): Store at 2–8 °C for short durations; prepare fresh when possible.
• Freeze–thaw: Not applicable to dehydrated powder. Do not freeze prepared agar plates, as freezing disrupts gel structure.

Research Use Note: For research use only (per Product Data).

Structure and Identity

LB Agar (Luria–Bertani agar) is a complex, undefined growth medium for cultivating bacteria (not a single, well-defined chemical entity).

• Item identity
  • Product type: Dehydrated culture medium (complex mixture) composed typically of tryptone (enzymatic digest of casein), yeast extract, sodium chloride, and agar as a gelling agent (literature; composition is general to LB media, not item-specific).
  • Molecular formula: Not applicable to mixtures. Item-specific value: Not specified for this item; refer to CoA/Spec Sheet.
  • Molecular weight: Not applicable to mixtures. Item-specific value: Not specified for this item; refer to CoA/Spec Sheet.
  • CAS, InChIKey, SMILES: Not applicable for complex media blends.
• Structural features (descriptive)
  • Contains a heterogeneous mixture of peptides, amino acids, vitamins, nucleotides, and minerals (from tryptone/yeast extract), NaCl to maintain osmotic balance, and agar, a linear polysaccharide (agarose/agn) that forms a thermo-reversible gel (literature, general).
  • No defined stereochemistry or single 2D structure; the product is a formulated blend intended for microbial culture.

Notes

• This product is sold for laboratory research and microbiology use; it is not intended for clinical or diagnostic applications.
• For exact composition ratios and performance characteristics of this SKU, consult the product CoA/specification sheet (item-specific details are not provided here).

Synthetic Utility

Not applicable in the context of organic synthesis. LB Agar is a complex microbiological medium and does not serve as a synthetic reagent, building block, or catalyst.

If your workflow involves chemical synthesis alongside microbiology, consider the following practical intersections (general):

• Screening of biosynthetic constructs or enzyme variants on LB agar supplemented with inducers/selective agents.
• Assaying transformation efficiency and library diversity prior to downstream chemical steps.

For chemical transformations, refer to solvent and reagent-specific content; LB Agar is outside the scope of synthetic utility.

Target Specificity

Not applicable. This product is not an antibody, probe, or targeted binding reagent. It is a general-purpose microbiological medium for cultivating a broad range of non-fastidious bacteria (literature, general).

Foire aux questions

How should this product be stored?

Store at room temperature.