Lactose Broth Medium (without pH Indicator) - BioReagent

Cat. No.: L1528768

GRADE & PURITY BioReagent

Storage

Room temperature

Shipped In

Normal

Overview

Without pH indicator, for coliform determination (USP), and also for Salmonella pre-enrichment (ISO)

Specifications

Specifications & Purity

BioReagent

Storage

Room temperature

Shipped In

Normal

Grade

BioReagent

Product Line

biological_products

Application Protocols

General literature workflow for lactose fermentation testing (indicator-free broth):

1. Preparation

• Dissolve the dehydrated medium in high-purity water at the formulation’s recommended concentration (item-specific value Not specified; refer to CoA/Spec Sheet). Typical literature concentration for lactose broth is ~13 g/L.
• Dispense into culture tubes; insert sterile Durham tubes (inverted) if assessing gas.
• Sterilize by autoclaving (121 °C, 15 min). Allow to cool; check Durham tubes for absence of pre-existing air bubbles.

2. Inoculation and Incubation

• Inoculate with test sample or a defined inoculum volume per method/SOP.
• Incubate at 35–37 °C for 24–48 h (literature), or per your validated protocol.

3. Readout

• Record gas production in Durham tubes as presumptive evidence of lactose fermentation.
• Because this product lacks a pH indicator, confirm acid production or organism identity by subculturing to differential/indicator media (e.g., MacConkey agar) or measuring pH instrumentally (literature).

4. Quality Controls

• Include positive (e.g., lactose-fermenting reference strain) and negative controls to validate performance.

5. Disposal

• Autoclave spent cultures prior to disposal as biohazard waste (literature).

Biological Roles

Although the product itself is not a biological macromolecule, it is designed to probe and support microbial metabolism in research contexts.

• Lactose fermentation (literature):
  • Many enteric bacteria metabolize lactose via beta-galactosidase (LacZ) after transport by LacY permease, generating glucose and galactose that enter glycolysis.
  • Fermentation end-products (e.g., acids, CO₂, H₂) vary by species/strain; gas detection in Durham tubes is a classic readout for coliform presumptive tests.
• Nutritional support:
  • Peptones/extracts supply amino acids, peptides, vitamins, and minerals that resuscitate stressed cells and support moderate biomass accumulation (literature).
• Indicator-free format:
  • Without an internal pH indicator, acid production is not visually signaled in-broth; users assess metabolism through gas formation and/or downstream plating on differential media (literature).
• Use cases: Study of carbohydrate utilization patterns, diauxic growth behavior (glucose vs lactose), and regulation of the lac operon under various environmental conditions (literature).

Buffer Applications

This product is not formulated as a buffer system; it is a nutrient medium with limited intrinsic buffering capacity.

• For experiments requiring defined pH control, use dedicated biological buffers (e.g., phosphate, MOPS, HEPES) prepared at the desired pH and ionic strength (literature).
• In lactose fermentation tests without an internal indicator, pH changes can be quantified by electrometric pH measurement or by transferring to differential indicator media (literature).

Green Alternatives

• Benign solvent system: Reconstitution is in water, a green solvent. No organic solvents are required (literature).
• Energy considerations: Autoclaving is energy-intensive; where appropriate, consider membrane sterilization of heat-labile supplements and minimizing sterilization cycles via batch preparation (balanced against contamination risk; literature).
• Waste minimization: Prepare only the volume needed to limit disposal of biohazardous broth. Decontaminate by autoclaving at end-of-life to enable safe disposal.
• Alternative media (functional, not greener per se):
  • Lauryl Tryptose Broth (LTB) can provide selectivity for coliforms, potentially reducing follow-up culturing steps.
  • Chromogenic coliform/enteric media can streamline workflows, lowering materials use and energy by reducing repeat tests.

Comparison (literature, qualitative):

• Lactose Broth: Non-selective, simple; supports broad lactose-fermenters; indicator-free → may require secondary tests.
• LTB/MacConkey: Selective/differential; may reduce repeats but include inhibitors/dyes.

Trade-offs: Simpler formulations avoid synthetic dyes/inhibitors, but may require additional culture steps. Selection should align with laboratory sustainability goals, organism targets, and SOP requirements.

Pharmaceutical Uses

• This product is intended for research use only. It is not an excipient, drug substance, or diagnostic.
• In pharmaceutical and biomanufacturing laboratories (research/QC contexts), lactose broth may be used in microbiological testing workflows such as pre-enrichment or presumptive fermentation assessments of environmental or process samples (literature). Any compendial suitability, if applicable, is Not specified for this item; refer to CoA/Spec Sheet and governing SOPs.
• No pharmacopeial grade or monograph compliance is claimed in this listing.

Physical Properties

• Form/Appearance: Not specified for this item; refer to CoA/Spec Sheet. (Typically supplied as a tan to light beige dehydrated powder; literature.)
• Solubility: Freely soluble in water (literature, for typical lactose broth media). Specific dissolution clarity for this item: Not specified; refer to CoA/Spec Sheet.
• pH (prepared medium): Not specified for this item; refer to CoA/Spec Sheet. (Typical lactose broth: pH ~6.8 ± 0.2 at 25 °C after sterilization; literature.)
• Osmolality/ionic strength: Not specified for this item; refer to CoA/Spec Sheet.
• Density, refractive index, logP, pKa, BP/MP: Not applicable/reported for complex media blends; Not specified for this item; refer to CoA/Spec Sheet.
• Autoclave stability: Complex nutrients are generally stable to standard sterilization cycles (121 °C, 15 min), though excessive time/temperature may darken the medium (Maillard reactions) and reduce growth performance (literature).
• Filterability: Prepared broth can be sterile-filtered through 0.22 µm membranes if heat-labile supplements are used (literature).

Quality & Grades

• Grade: BioReagent (as provided). This denotes suitability for general biological and biochemical research workflows where consistent growth performance and low inhibitory contaminants are important.
• What BioReagent implies (general):
  • Manufactured under controlled conditions for laboratory research use.
  • Emphasis on reproducibility of performance (e.g., growth promotion, lactose fermentation response) rather than analytical trace-metal minima typical of high-purity chemical reagents.
  • Not intended for clinical diagnostics or therapeutic use.
• UV absorbance/metal limits/peroxides/residual solvents: Not specified for this item; refer to CoA/Spec Sheet.
• Stabilizers/antimicrobials: None implied; growth media are typically free of inhibitors unless explicitly stated. Not specified for this item; refer to CoA/Spec Sheet.
• Lot-specific verification: For media, functional QC often includes growth/fermentation performance with challenge strains (literature). For this item, specific QC metrics are Not specified; refer to CoA/Spec Sheet.
• Documentation: For regulatory or QA environments, retain the lot CoA and SDS; perform in-house growth promotion tests when required by SOPs.

Reaction & Applications

This item is a microbiological medium rather than a chemical reagent. It is not typically used as a substrate or solvent for organic synthesis.

Applicable laboratory applications (literature):

• Presumptive coliform testing via lactose fermentation with Durham tubes to detect gas production.
• Pre-enrichment step for food/water/environmental samples where recovery of stressed lactose-fermenting organisms is desired.
• Quality control of sanitation processes by monitoring lactose-fermenting bacterial loads.
• Metabolic studies of carbohydrate utilization, beta-galactosidase induction, and acid/gas yields in enteric bacteria, using external pH indicators or secondary differential media because this formulation is “without pH indicator.”

Practical tips (literature):

• Completely dissolve the medium in purified water; distribute to tubes with Durham vials if gas detection is needed; sterilize (e.g., 121 °C, 15 min). Avoid overheating which can caramelize sugars.
• For acid detection in an indicator-free broth, perform post-incubation subculture to indicator media (e.g., BCP-lactose broth, MacConkey agar) or measure pH electrometrically.
• Include positive and negative control strains per SOP to validate fermentation readouts.

Reaction Conditions

Chemical reaction parameters are not applicable to this product. For culture preparation and incubation, the following are general literature guidelines (not item specifications):

• Reconstitution concentration (literature): Typical lactose broth formulations are prepared at approximately 13 g per liter of water (based on common compositions of peptone, beef extract, lactose). This item’s exact preparation is Not specified; refer to CoA/Spec Sheet.
• Sterilization (literature): Autoclave at 121 °C for 15 minutes. Avoid prolonged sterilization to minimize sugar degradation.
• Incubation (literature): 35–37 °C for 24–48 h for coliform/lactose-fermenter assessments, with Durham tubes if gas detection is desired.
• Controls: Include positive and negative control strains as dictated by SOPs.

Always adapt conditions to your validated method and consult the CoA/Spec Sheet for any item-specific instructions.

Safety & Handling

• GHS/Signal word/Pictograms/H-statements: Not specified for this item; refer to SDS.
• General hazards (literature/good practice):
  • Dehydrated culture media may produce nuisance dust; avoid inhalation. Use in a well-ventilated area or biological safety cabinet when handling microbiological inocula.
  • Not intrinsically sterile; once reconstituted, medium will support microbial growth—treat as biohazardous after inoculation. Decontaminate by autoclaving prior to disposal.
• Incompatibilities: Avoid strong oxidizers contacting the dry blend and prepared broth (literature). Do not autoclave in sealed containers; pressure buildup risk.
• PPE: Laboratory coat, gloves, and splash-resistant eye protection. Upgrade PPE when manipulating unknown or pathogenic cultures according to institutional biosafety level (BSL) policies.
• First aid (overview; refer to SDS): Rinse eyes/skin with water if contacted. If inhaled, move to fresh air. If ingested, rinse mouth; seek medical advice if symptoms persist.
• Spill response: For dry powder, avoid dust generation; sweep with minimal disturbance. For broth containing microbes, cover with disinfectant (e.g., freshly prepared 10% bleach), allow adequate contact time, then absorb and discard as biohazard waste (literature).
• Always consult the product SDS for authoritative safety information.

Solvent Selection

This product is a culture medium intended for reconstitution in water; organic solvent selection is not applicable.

• Recommended solvent: High-purity water (e.g., ASTM Type I/II, 18 MΩ·cm DI) to minimize inhibitory ions and chlorine/chloramine residuals (literature).
• Miscibility: The dehydrated blend is designed to fully dissolve/disperse in water at the specified formulation concentration (item-specific details Not specified; refer to CoA/Spec Sheet).
• Water quality considerations (literature):
  • Avoid high residual oxidants (free chlorine, ozone) and heavy metal contamination; if using municipal water, pre-treatment (activated carbon/RO) is recommended.
  • Adjust pH only after complete dissolution; avoid strong base/acid that can degrade amino acids/sugars.
• When to choose vs alternatives:
  • Use lactose broth when assessing lactose fermentation and gas production by coliforms or other lactose-positive organisms.
  • For selective/differential needs, consider media with inhibitors or chromogens (e.g., Lauryl Tryptose Broth, MacConkey Broth/Agar; literature).

Storage & Reconstitution

• Storage (as supplied): Room temperature (per product data). Protect from moisture and microbial contamination by keeping the container tightly closed. Avoid prolonged exposure to humidity and heat sources.
• Shipping: Shipped at ambient temperature (per product data: Normal).
• Shelf life: Not specified for this item; refer to CoA/Spec Sheet.
• Reconstitution:
  • Solvent: High-purity water. Item-specific concentration is Not specified; refer to CoA/Spec Sheet.
  • Literature guidance: Typical lactose broth is prepared at ~13 g/L; mix until fully dissolved. Adjust pH only if directed by your method; avoid strong base/acid.
  • Sterilize by autoclaving (121 °C, 15 min) unless using sterile filtration for heat-labile supplements (literature).
• Prepared medium storage (literature): Store sterile broth at 2–8 °C for short-term use; warm to room temperature before inoculation. Inspect for turbidity, precipitation, or color change prior to use.
• Freeze–thaw: Not applicable; avoid freezing prepared broth unless validated for your assay.

For any item-specific preparation instructions, concentrations, and performance criteria, consult the product’s CoA/Spec Sheet.

Structure & Identity

Lactose Broth Medium (without pH Indicator) is a dehydrated microbiological medium, i.e., a formulated mixture rather than a single defined compound.

• Item type: Complex culture medium (mixture); not a single molecule
• Molecular formula / MW / SMILES / InChIKey: Not applicable to mixtures; Not specified for this item; refer to CoA/Spec Sheet.
• CAS / CID: Not applicable to the complete medium blend; Not specified for this item; refer to CoA/Spec Sheet.
• Composition: Not specified for this item; refer to CoA/Spec Sheet. (Typical lactose broth compositions are provided as literature context below.)
• Structural features (descriptive, literature):
  • Contains a fermentable carbohydrate (lactose) serving as a carbon source.
  • Peptone/tryptone (enzymatic digests) provide amino acids/peptides and growth factors (complex, undefined fraction).
  • Meat/yeast extracts (if present) contribute vitamins, nucleotides, and minerals.
• 2D description: As a heterogeneous blend of low-molecular-weight nutrients and peptides, the product has no single definable 2D structure; individual components (e.g., lactose) are small organic molecules, while peptones are polydisperse peptide mixtures.

Note: This listing specifies “without pH Indicator,” meaning no internal colorimetric indicator (e.g., bromocresol purple) is included; detection of lactose fermentation typically relies on gas production (Durham tube) or secondary indicator media (literature).

Synthetic Utility

Not applicable. Lactose Broth Medium is not employed as a reagent or building block in chemical synthesis.

• For carbohydrate chemistry or peptide synthesis, use defined reagents rather than complex nutrient blends.
• The medium’s role is biological culture support; see Reaction & Applications and Application Protocols for relevant laboratory usage.

Target Specificity

Not applicable. This product is not an antibody, enzyme inhibitor, or targeted probe. It is a general-purpose nutrient medium for cultivating and assessing lactose fermentation by microorganisms (research use).

Frequently Asked Questions

How should this product be stored?

Store at room temperature.