LB Broth - BioReagent

Cat. No.: L1528313

GRAU & PUREZA BioReagent

Storage

Room temperature

Shipped In

Normal

Visão geral

Contains 1% NaCl, for the cultivation of Escherichia coli in molecular biology

Especificações

Especificações e pureza

BioReagent

Condições de armazenamento de armazenamento

Room temperature

Enviado em

Normal

Grau

BioReagent

Product Line

Produtos biológicos

Application Protocols

No item-specific, validated protocols are provided. The following are general literature practices; verify and adapt to your system.

• Liquid culture (starter/overnight)
  • Reconstitute LB at the recommended concentration (e.g., 20–25 g/L; literature). Sterilize and cool. Inoculate with a single colony or glycerol stock. Incubate 12–16 h at 30–37 °C with shaking (200–250 rpm).
• LB agar plates with antibiotic selection
  • Prepare LB agar, sterilize, cool to ~50 °C, add antibiotic stock to desired concentration, mix, and pour 20–25 mL per 100 mm plate. Allow to set and dry before use. Store plates at 2–8 °C, wrapped to prevent desiccation (storage conditions for plates are general; not item-specific).
• Plasmid miniprep culture
  • Inoculate 3–5 mL LB with selected colony; incubate overnight. Proceed with standard alkaline lysis miniprep the next day.
• Glycerol stocks
  • Grow cells to late log/early stationary, mix culture 1:1 with sterile 30–50% glycerol to a final 15–25% glycerol, aliquot, and freeze at −80 °C.

Item-specific preparation and QC acceptance criteria are Not specified for this item; refer to CoA/Spec Sheet.

Biological Roles

LB Broth functions as a nutrient source that supports bacterial metabolism and proliferation (general literature).

• Component roles (typical formulations)
  • Tryptone (peptone): Provides peptides, amino acids, and small peptides that fuel biosynthesis and energy metabolism.
  • Yeast extract: Supplies vitamins (e.g., B-complex), nucleotides, trace elements, and growth factors enhancing overall growth rate.
  • Sodium chloride: Maintains osmotic balance, supports transport processes, and influences membrane potential.
• Microbial physiology considerations
  • Carbon/nitrogen balance: LB is relatively nitrogen-rich and carbon-limited compared with richer/defined media, leading to moderate final cell densities and early stationary phase.
  • pH drift: Organic acid production and ammonia release can shift pH during growth; unbuffered LB shows limited pH control, which can affect gene expression and plasmid stability.
  • Stress responses: NaCl concentration modulates osmotic stress pathways; variant selection (Miller vs Lennox) can be used to probe osmoadaptation.
• Use cases in molecular biology
  • Supports maintenance of plasmids under selection with appropriate antibiotics; nutrient profile is adequate for routine cloning and screening.

These roles describe LB in general; specific performance characteristics for this item are Not specified for this item; refer to CoA/Spec Sheet and verify in your system.

Buffer Applications

LB Broth is not a buffer system; it is a nutrient-rich, weakly buffered medium.

• General notes (literature)
  • Typical unbuffered LB exhibits limited buffering capacity around neutral pH. During active growth, pH can drift from ~7 toward acidic or alkaline depending on metabolism.
  • For applications requiring stable pH (e.g., expression of pH-sensitive proteins), supplement LB with a buffering agent such as phosphate (e.g., 50–100 mM) or MOPS/HEPES, or use a dedicated buffered medium.
• Practical guidance
  • If buffering is added, adjust pH prior to sterilization and confirm post-autoclave pH, as heat can shift pH.
  • Antibiotic stability can be pH-dependent; verify compatibility when modifying buffer systems.

Item-specific pH/buffering attributes are Not specified for this item; refer to CoA/Spec Sheet.

Green Alternatives

While LB Broth is already water-based and free from volatile organic solvents, sustainability considerations focus on energy use, waste minimization, and sourcing.

• Strategies to reduce environmental impact (literature/best practice)
  • Prepare only the volume needed to avoid disposal of unused sterile media.
  • Use energy-efficient autoclave cycles and load consolidation; consider validated shorter cycles when appropriate.
  • Filter sterilization (0.22 µm) can reduce energy use for heat-labile supplements but generates plastic waste—balance trade-offs.
  • Reuse glassware (flasks, bottles, pipettes) where permitted to minimize single-use plastics in culture workflows.
  • Choose low-salt LB variants if osmolality is non-critical to reduce sodium load in effluent.

Comparison (literature, general)

• Option: Standard LB vs Buffered LB
  • Standard LB: Simpler, fewer salts; lower buffer capacity; less chemical input.
  • Buffered LB (e.g., with phosphate/MOPS): Better pH stability, potentially higher biomass; slightly higher chemical load and phosphate in waste stream.
• Option: Powder you reconstitute vs pre-made liquid
  • Powder: Lower shipping weight and packaging; less storage volume; requires sterilization on site.
  • Pre-made liquid: Convenience; higher shipping mass; often more packaging waste.

Note: No composition details specific to this item are provided; implement lab-level green practices appropriate to your facility.

Pharmaceutical Uses

No therapeutic use is implied. LB Broth is for research use only (per product data) and is commonly employed in non-clinical, laboratory contexts.

• Typical roles in regulated/industrial environments (general literature)
  • Microbiological workflows in R&D and quality control labs: maintenance and cultivation of non-fastidious bacterial strains used as assay organisms or production hosts.
  • Vector and strain construction in process development for recombinant protein or plasmid DNA manufacture (developmental stages).
  • Environmental or utility monitoring may use other compendial media; LB is generally not a compendial test medium.
• Compliance note
  • When media are used in GMP/GLP settings, compendial conformity, vendor qualification, and growth promotion testing are typically required. This listing does not assert compendial status.

Item-specific regulatory or compendial designations: Not specified for this item; refer to CoA/Spec Sheet.

Physical Properties

LB Broth is supplied as a dehydrated, complex powder (mixture). Discrete physicochemical constants are not applicable to the mixture as a whole.

• Item-specific specifications
  • Appearance: Not specified for this item; refer to CoA/Spec Sheet.
  • pH (as prepared): Not specified for this item; refer to CoA/Spec Sheet.
  • Any numeric specs (water, ash, metals): Not specified for this item; refer to CoA/Spec Sheet.
• General/literature characteristics (non-binding)
  • Physical state: Free-flowing powder; forms a clear to slightly opalescent solution after dissolution and sterilization.
  • Solubility: Freely soluble in water; insoluble in nonpolar solvents (literature).
  • Typical preparation concentrations: 20–25 g/L for LB “Broth” working strength; 35–40 g/L for LB Agar with 15 g/L agar added (literature). Exact preparation for this item is Not specified; refer to CoA/Spec Sheet.
  • Typical pH after sterilization (literature): ~7.0 ± 0.5 at 25 °C (formulation dependent; Miller vs Lennox can differ slightly).
  • Osmolality (literature, formulation dependent): increases with NaCl content; LB Miller ~200–300 mOsm/kg; Lennox lower due to 5 g/L NaCl.
  • Appearance of prepared medium (literature): pale yellow solution; agar plates are light amber.

Always confirm preparation instructions and acceptance criteria with the item’s CoA/Spec Sheet; the above values are literature ranges and not item specifications.

Quality and Grades

• Item-specific grade
  • Grade: BioReagent (as provided). This denotes suitability for general life science workflows and routine microbiology/molecular biology where consistent growth performance is required.
• What BioReagent typically implies (general guidance)
  • Manufactured to support biological experiments with attention to lot-to-lot performance (e.g., growth curves, colony morphology, plasmid yield) rather than analytical trace impurity limits.
  • May include in-process controls such as solubility, pH of prepared medium, sterility (if sterilized product), and growth promotion testing with representative strains (literature practices). Exact QC for this item: Not specified for this item; refer to CoA/Spec Sheet.
• Stabilizers and additives
  • No stabilizers are indicated for this item. Any stabilizers or anti-caking agents: Not specified for this item; refer to CoA/Spec Sheet.
• Choosing LB variants (general)
  • Select NaCl level (Miller vs Lennox vs Low Salt) based on downstream needs (e.g., salt-sensitive antibiotic selection, osmotic stress studies).
  • For plasmid production and protein expression, verify that the medium supports desired growth kinetics and induction strategy.

Note: For regulatory microbiology (e.g., pharmacopeial media), consult and match specific compendial formulations and QC; this listing does not claim compendial compliance unless stated on the CoA.

Reaction and Applications

LB Broth is a general-purpose, nutritionally rich medium widely used in microbiology and molecular biology.

• Core applications (literature)
  • Routine cultivation of Escherichia coli and other non-fastidious bacteria in liquid culture or as agar plates (with agar added).
  • Cloning workflows: growth of transformants post-heat shock/electroporation (often SOC for recovery, then LB for selection plates with antibiotics).
  • Plasmid DNA preparation: overnight cultures for miniprep/midiprep; moderate biomass and plasmid yield compared with richer media.
  • Protein expression in E. coli: inoculum preparation, small-scale expression tests; many protocols use LB for induction screens prior to scaling in richer media.
  • Phage work and general bacteriology teaching labs.
• Practical tips (literature)
  • Salt selection: Miller (10 g/L NaCl) vs Lennox (5 g/L NaCl) can affect antibiotic activity (e.g., carbenicillin stability) and osmotically stress cells.
  • Antibiotics: Sterile-filter stocks; add to cooled (~45–55 °C) autoclaved medium to avoid degradation. Typical plate concentrations vary by antibiotic/class.
  • Aeration: For liquid cultures, use 1:5 to 1:10 flask fill ratios and vigorous shaking (200–250 rpm) to maintain oxygen transfer. Baffles further improve aeration.
  • Induction: If used for expression, monitor OD600; LB saturates at lower densities than TB/autoinduction media.
  • Colony morphology: LB agar supports robust colony formation; dry plates briefly before spreading to prevent lawns.

Note: Exact performance characteristics for this item are Not specified; consult CoA/Spec Sheet and validate in your system.

Reaction Conditions

Classical chemical reaction condition guidance is not applicable to LB Broth. However, preparation and sterilization conditions for microbiological use are relevant (literature; non-binding).

• Typical preparation (example; verify with CoA/Spec Sheet)
  • Dissolve the recommended grams of LB powder per liter of water (commonly 20–25 g/L for broth, depending on variant). Mix until fully dissolved.
  • For plates, add agar (typically 15 g/L) before sterilization.
• Sterilization
  • Autoclave at 121 °C for 15–20 minutes. Do not autoclave heat-labile components (e.g., antibiotics, certain sugars); sterile-filter these and add aseptically after cooling to ~45–55 °C (for agar) or to room temperature (for broth).
• Culture conditions (typical ranges; literature)
  • Incubation temperature for E. coli: 30–37 °C depending on strain and expression needs.
  • Shaking: 200–250 rpm with adequate headspace (1:5 to 1:10 fill) for aeration in baffled or non-baffled flasks.
  • Expected OD600 saturation in LB: lower than in richer media; monitor growth and avoid overgrowth for plasmid stability.

These are general guidelines; exact instructions for this item are Not specified; refer to CoA/Spec Sheet.

Safety and Handling

• GHS classification (item-specific)
  • Signal word: Not specified for this item; refer to SDS.
  • Hazard statements (H-codes): Not specified for this item; refer to SDS.
  • Pictograms: Not specified for this item; refer to SDS.
• General laboratory safety (good practice)
  • PPE: Laboratory coat, safety glasses, and appropriate gloves when handling powder and prepared media. Avoid inhalation of dust; handle in a well-ventilated area or fume hood during weighing.
  • Hygiene: Wash hands after handling. Decontaminate work surfaces to prevent microbial contamination.
• Microbiological considerations
  • LB supports microbial growth; treat used medium as biohazardous. Autoclave spent or contaminated media before disposal per institutional biosafety procedures.
  • Avoid cross-contamination: Use sterile technique; use sterile containers and closures.
• Incompatibilities and special risks
  • Moisture sensitivity: Keep container tightly closed to prevent caking and microbial contamination of the powder.
  • Thermal processing: Sterilize by autoclaving (typ. 121 °C, 15–20 min; literature). Do not autoclave heat-labile supplements (e.g., antibiotics); filter-sterilize and add after cooling.
  • Pressure vessels: Do not overfill or tightly cap vessels during autoclaving; allow venting to prevent explosion hazards.
• First aid (overview; defer to SDS)
  • Inhalation: Move to fresh air; seek medical advice if irritation persists.
  • Skin/eye contact: Rinse with water. Remove contaminated clothing. Seek medical advice if irritation persists.

Always consult the product SDS for authoritative safety information.

Solvent Selection

LB Broth is reconstituted in water to prepare an aqueous medium.

• Primary solvent
  • Ultrapure water (e.g., ASTM Type 1/2) is recommended to minimize variability from ions and organics (general best practice).
• Miscibility profile (literature)
  • The dehydrated powder dissolves readily in water with stirring; not intended for nonaqueous solvents.
  • Alcohols or organic co-solvents are not used for routine LB preparation as they inhibit microbial growth.
• Practical guidance
  • Pre-warm water (room temperature) and add powder slowly under vigorous stirring to prevent clumping.
  • Adjust volume after dissolution; check pH only if your protocol specifies. Most LB formulations require no pH adjustment prior to sterilization.
  • For agar plates, dissolve agar separately or co-dissolve with LB by heating; ensure complete melting prior to sterilization and pouring.
• When to choose alternatives
  • For rich growth or buffering, consider TB, 2xYT, or SOC (literature), or add buffering components (e.g., phosphate) if pH stability is essential. For salt-sensitive selections, prefer LB Lennox/Low Salt.

Item-specific solvent or preparation instructions: Not specified for this item; refer to CoA/Spec Sheet.

Storage and Reconstitution

• Item-specific storage
  • Storage conditions: Room temperature (as provided in product data). Protect from moisture and contamination. Keep container tightly closed.
  • Shipped in: Normal (ambient) conditions (as provided).
• Reconstitution (general literature guidance; not item-specific)
  • Weigh the recommended amount of LB powder per liter (commonly 20–25 g/L for broth, depending on variant; exact value Not specified for this item; refer to CoA/Spec Sheet).
  • Add to ~80–90% of final volume of purified water with vigorous stirring until dissolved. Bring to final volume.
  • For agar, add ~15 g/L agar before sterilization if preparing plates.
  • Sterilize by autoclaving at 121 °C for 15–20 min. Allow to cool. If adding antibiotics or other heat-labile supplements, sterile-filter these and add aseptically after cooling (≈45–55 °C for agar media; room temperature for broth).
  • Pour plates in a sterile environment; let solidify and dry lids ajar to remove surface moisture before storage.
• Stability (general)
  • Store prepared broth at 2–8 °C for short periods (days to a week) to limit contamination; prepared plates typically store 2–4 weeks at 2–8 °C when wrapped/sealed to prevent desiccation.

For exact preparation instructions, concentrations, and acceptance criteria for this item, consult the CoA/Spec Sheet. Research use only (per product data).

Structure and Identity

LB Broth (Luria–Bertani medium) is a complex, undefined microbiological growth medium rather than a single chemical entity.

• Item-specific identifiers
  • CAS: Not specified for this item; refer to CoA/Spec Sheet.
  • Molecular formula: Not applicable (mixture); Not specified for this item; refer to CoA/Spec Sheet.
  • Molecular weight: Not applicable (mixture); Not specified for this item; refer to CoA/Spec Sheet.
  • SMILES / InChIKey: Not applicable for complex mixtures.
• Structural description (general literature)
  • LB Broth typically contains a peptone (tryptone; pancreatic digest of casein), yeast extract (source of vitamins, nucleotides, and growth factors), and sodium chloride.
  • Being a mixture of peptides, amino acids, carbohydrates, salts, and vitamins, LB has no single defined structure and lacks a discrete 2D representation.
• Common variants (literature)
  • LB Miller: 10 g/L tryptone, 5 g/L yeast extract, 10 g/L NaCl.
  • LB Lennox: 10 g/L tryptone, 5 g/L yeast extract, 5 g/L NaCl.
  • LB Low Salt: 10 g/L tryptone, 5 g/L yeast extract, 0–5 g/L NaCl.

Note: Exact composition, if formulation-specific, is Not specified for this item; refer to CoA/Spec Sheet.

Synthetic Utility

This product is a complex biological growth medium and is not typically used as a reagent in synthetic organic or inorganic chemistry.

• Non-applicability
  • It does not serve as a solvent, catalyst, or reactant in chemical synthesis.
  • Key sections relevant to this product are Reaction & Applications, Biological Roles, and Storage & Reconstitution rather than synthetic transformations.

For chemical synthesis needs, consult appropriate solvents, reagents, or catalysts designed for those applications.

Target Specificity

Not applicable. This product is a general microbiological medium and does not possess target specificity (e.g., antigen/epitope, clone, isotype). It supports growth of many non-fastidious bacteria; selectivity arises only when combined with antibiotics or other selective agents, which are not included unless explicitly stated (not specified for this item).