MacConkey Broth - BioReagent

Cat. No.: M1523321

GRAU & PUREZA BioReagent

Storage

Room temperature

Shipped In

Normal

Visão geral

Used for selective enrichment culture of Escherichia coli.

Especificações

Especificações e pureza

BioReagent

Condições de armazenamento de armazenamento

Room temperature

Enviado em

Normal

Grau

BioReagent

Product Line

Produtos biológicos

Application Protocols

Note: No item-specific validated protocols provided. The following is general literature guidance for MacConkey Broth and should be adapted to your SOPs.

A. Preparation of MacConkey Broth (1 L)

• Weigh 35–40 g dehydrated medium into a clean flask.
• Add ~900 mL purified water. Heat with stirring until fully dissolved; bring volume to 1 L.
• Dispense into tubes/flasks (insert sterile Durham tubes if gas detection is required).
• Autoclave at 121 °C for 15 min. Cool to room temperature before use.

B. Inoculation and Incubation

• Aseptically inoculate with test sample or control strains. Cap loosely to allow gas exchange if using Durham tubes.
• Incubate at 35–37 °C for 18–24 h.

C. Interpretation

• Turbidity indicates growth. Acid production from lactose fermentation produces a distinct indicator color shift (literature) and, with Durham tubes, potential gas accumulation.
• For confirmation/identification, streak from positive broths onto MacConkey Agar or other differential/confirmatory media and run biochemical tests as required.

Controls and QA

• Include positive (lactose-fermenter) and negative (non-fermenter and Gram-positive) controls each run to verify selectivity and differential performance.

Biological Roles

Applicability note

• MacConkey Broth is not a single biomolecule and has no intrinsic metabolic role. This section summarizes its function within microbiological workflows (literature).

Functional role in microbiology

• Selective pressure: Bile salts and crystal violet suppress many Gram-positive organisms, enriching Gram-negative enterics from mixed samples.
• Differential indicator system: Lactose as a fermentable carbohydrate and a pH indicator (often neutral red) enable phenotypic discrimination based on acid production.
• Nutritional support: Peptones/tryptones supply amino acids, peptides, vitamins, and minerals required for growth of non-fastidious Gram-negative rods.

Use cases

• Enrichment step prior to isolation on solid selective/differential media.
• Assessment of lactose fermentation and gas production when used with Durham tubes in research and method development.

Limitations and considerations

• Fastidious organisms may require enriched media. Some Gram-negative species are inhibited or grow poorly depending on bile salt concentration and dye sensitivity. Phenotypic variability can yield atypical reactions, necessitating confirmatory testing.

Buffer Applications

Not typically applicable

• MacConkey Broth is not intended for use as a chemical buffer. While the prepared medium exhibits a controlled pH due to its formulation (literature pH target often ~7.1), it lacks the defined buffering capacity and composition required for biochemical assays.

Guidance

• For buffering needs, select defined buffer systems (e.g., phosphate, HEPES, Tris) tailored to your pH and ionic strength requirements. Use MacConkey Broth strictly for microbiological culture and differential testing.

Green Alternatives

Context

• MacConkey Broth is an aqueous, solvent-free system by design. Green considerations focus on preparation efficiency, waste minimization, and safer components.

Greener practice suggestions (literature)

• Prepare only the volume needed to reduce wasted sterilized medium. Use energy-efficient autoclave cycles validated for your load size.
• Consider reusable glassware and validated cleaning protocols to minimize single-use plastics for media preparation, while maintaining sterility and safety.
• Use high-efficiency particulate air (HEPA) filtration or local exhaust during powder handling to protect workers rather than relying solely on single-use PPE.
• Dispose of spent media via validated autoclave/chemical disinfection procedures that minimize hazardous chemical use; segregate by contamination class to avoid over-treatment.

Comparative considerations

• Ready-to-use bottled broth vs dehydrated medium: Dehydrated media reduce shipping weight/volume and packaging; on-site reconstitution lowers carbon footprint but requires autoclave energy.
• Alternative selective media: Chromogenic enteric broths/agar can streamline workflows, potentially reducing confirmatory tests (less resource use) but may involve specialty dyes with their own environmental profiles.

Trade-offs

• Strong selectivity agents (e.g., crystal violet, bile salts) are efficacious but introduce dye/surfactant waste. Ensure compliant waste management and avoid spills to drains without treatment.

Pharmaceutical Uses

Scope and restriction

• For research use only (from Product Data). No clinical or diagnostic claims are made.

Relevant roles in pharmaceutical/biotech labs (literature)

• Microbiology QC and environmental monitoring research: Enrichment/differentiation of Gram-negative organisms from non-sterile samples in method development and suitability studies.
• Raw material or water system investigations in R&D: Phenotypic screening for lactose-fermenting coliform-like organisms.
• Training and validation exercises: Media preparation proficiency, growth promotion testing (GPT) studies, and procedural controls.

Standards and compendia

• While MacConkey-type media are described in microbiology references and compendial contexts, suitability for a regulated application depends on the exact formulation and documented performance. Consult your method, CoA, and SOPs to determine acceptability.

Physical Properties

Item-specific facts (from Product Data)

• Appearance: Not specified for this item; refer to CoA/Spec Sheet.
• Storage conditions: Room temperature (as supplied, dehydrated powder).

Typical properties (literature; not item-specific specifications)

• Physical form: Dehydrated, free-flowing powder composed of peptones, bile salts, lactose, and indicator dyes.
• Solubility: Readily soluble in water at the recommended preparation concentration (commonly 35–40 g/L). Complete dissolution may require warming and mixing.
• Prepared-medium pH (at 25 °C): Often formulated to pH ~7.1 ± 0.2 before sterilization; final pH may vary with brand and preparation.
• Color (prepared): Light red to rose due to neutral red; intensity depends on exact formulation.
• Thermal stability: Dehydrated base is stable at ambient conditions if kept dry and sealed; the prepared medium is heat-sterilized (commonly autoclaved at 121 °C for ~15 min) and then used or stored refrigerated for short periods.
• Osmolality/ionic strength: Not standardized; depends on peptone and salt content across suppliers.

Notes

• Since this is a complex, undefined mixture, attributes such as exact molecular weight, logP, refractive index, and definitive BP/MP are not meaningful and are generally not reported for culture media.

Quality and Grades

Item-specific facts (from Product Data)

• Grade/Purity: BioReagent.

What BioReagent grade typically implies (general)

• BioReagent-grade media components are suitable for research and laboratory microbiology workflows, emphasizing consistency, low bioburden, and performance in culture applications. While not a clinical/diagnostic claim, this grade supports routine enrichment, differentiation, and QC assays in research settings.
• Performance attributes (general): Lot-to-lot consistency of growth promotion and selectivity, clarity/color of prepared medium within expected ranges, and pH within target after sterilization (literature expectations).

Stabilizers/additives

• Stabilizers: Not specified for this item; refer to CoA/Spec Sheet.

Release testing (general guidance)

• Typical QC for MacConkey-type media includes growth promotion tests with representative organisms (e.g., Escherichia coli as a lactose fermenter and Salmonella spp. as a non-fermenter) and inhibitory testing vs Gram-positive strains (due to bile salts/crystal violet). Specific acceptance criteria are supplier-specific and should be confirmed on the CoA.

Use context

• Research Use Only (from Product Data). Not for human or animal diagnostic or therapeutic use.

Reaction and Applications

Scope note

• This section addresses laboratory applications rather than chemical reactions, as MacConkey Broth is a microbiological medium.

Applications (literature)

• Selective enrichment of Gram-negative enteric bacteria via bile salts and crystal violet inhibition of many Gram-positive organisms.
• Differential detection of lactose fermentation: Acid production lowers pH, shifting the indicator. In broths with Durham tubes, gas production (CO2) can also be observed.
• Monitoring water/food/environmental samples for coliforms and related enterics in research settings and laboratory method development.

Practical tips

• Inoculum size: Avoid over-inoculation that overwhelms selectivity. Use appropriate dilutions for mixed samples.
• Incubation: 35–37 °C for 18–24 hours (literature). Aerobic conditions are typical, but microaerophilic nuances depend on organism.
• Readout: Observe turbidity and color change; subculture to MacConkey Agar or other differential media for isolation and confirmation.
• Controls: Include a known lactose fermenter (e.g., E. coli) and a non-fermenter (e.g., Salmonella spp.) to verify medium performance each run.

Limitations

• Some organisms may be inhibited or yield atypical reactions depending on strain and inoculum. Confirmatory biochemical tests are advised for identification. Adjust incubation time/temperature per method requirements.

Reaction Conditions

Interpretation note

• Here, “conditions” are presented as culture conditions relevant to MacConkey Broth use (literature), not chemical reaction parameters.

Typical culture conditions (literature; adjust per method)

• Preparation: Dissolve approximately 35–40 g of dehydrated medium per liter of purified water. Heat with agitation to dissolve. Adjust pH only if specified by your method. Dispense into suitable vessels (with or without Durham tubes).
• Sterilization: Autoclave at 121 °C for ~15 minutes. Avoid prolonged sterilization that may degrade lactose or indicator dyes.
• Inoculation: Introduce test sample aseptically. Employ appropriate dilutions to avoid overwhelming selective agents.
• Incubation: 35–37 °C for 18–24 hours under aerobic conditions unless method specifies otherwise.
• Readout: Observe turbidity, color change consistent with acid production, and gas in Durham tubes (where used). Subculture to selective/differential agar for isolation and further testing as needed.

Expected outcomes/controls

• Positive control: Known lactose fermenter (e.g., Escherichia coli) should exhibit growth and acid production (indicator color shift).
• Negative/selectivity control: Non-fermenter (e.g., Salmonella spp.) may grow without acid shift; Gram-positive control (e.g., Staphylococcus aureus) should be inhibited. Actual responses can vary by strain and formulation.

Safety and Handling

Item-specific hazard data

• Signal word, H-statements, GHS classification, pictograms: Not specified for this item; refer to the SDS for authoritative safety information.

General safety guidance (literature; not a substitute for the SDS)

• PPE: Laboratory coat, gloves (nitrile), and safety glasses recommended. Avoid creating or inhaling dust during weighing and mixing.
• Handling: Use in a clean environment to prevent contamination. When preparing large batches, employ local exhaust ventilation to minimize dust exposure.
• Incompatibilities: Strong oxidizing agents may interact with organic components. Avoid contact with strong acids/bases that could degrade indicator dyes or peptones.
• Microbiological considerations: Once inoculated, the medium can contain viable microorganisms. Treat all used media and culture waste as biohazard; autoclave before disposal per institutional biosafety procedures.
• Special risks: Some formulations include crystal violet and bile salts; dyes can stain skin and surfaces. Neutral red and crystal violet have hazard profiles; avoid skin/eye contact and ingestion. Handle powders and prepared media accordingly.
• First aid (overview): If inhaled (dust), move to fresh air; if on skin or in eyes, rinse with water for several minutes; if ingested, rinse mouth. Seek medical advice as needed. Always follow institutional safety policies.

Shipping/storage from Product Data

• Shipped: Normal. Store the dehydrated medium at room temperature in a tightly closed container, protected from moisture.

Solvent Selection

Applicability note

• Solvent selection in the classic organic-chemistry sense does not apply. MacConkey Broth is formulated for aqueous reconstitution only.

Practical guidance (literature)

• Water quality: Use freshly prepared, deionized or distilled water that meets ASTM Type II or better for microbiological media. Avoid high TOC or residual disinfectants (e.g., chlorine/chloramine) that may inhibit growth.
• Reconstitution: Typical preparation uses 35–40 g of dehydrated medium per liter of water (per literature), with gentle heating and stirring to ensure full dissolution before sterilization.
• Sterilization: Autoclaving at 121 °C for ~15 minutes is standard unless the formulation specifies otherwise. Do not overheat to prevent indicator degradation.
• Additives: If antibiotics or supplements are required for specific workflows, filter-sterilize those solutions and add aseptically after the medium cools to ~45–50 °C.

Comparison to alternatives (literature)

• MacConkey Agar vs Broth: Agar includes ~15 g/L agar to produce a solid, differential plating medium. Broth is for enrichment/detection in liquid culture.
• Lactose vs sorbitol MacConkey: Sorbitol versions are used for specialized applications (e.g., differentiation among E. coli strains). Choose the formulation aligned with your organism/assay requirements.

Storage and Reconstitution

Item-specific storage (from Product Data)

• Storage conditions (as supplied): Room temperature. Keep container tightly closed and protect from moisture.
• Shipped: Normal.

General reconstitution guidance (literature; verify with your SOP/CoA)

• Preparation ratio: Commonly 35–40 g of dehydrated MacConkey Broth per liter of purified water. Heat gently with stirring to dissolve completely.
• Sterilization: Autoclave at 121 °C for ~15 minutes. Do not over-sterilize to avoid indicator/carbohydrate degradation.
• Post-sterilization handling: Allow to cool to ambient before use. If adding heat-labile supplements, cool to ~45–50 °C and add aseptically through a 0.2 µm filter.
• Short-term storage of prepared medium: Store at 2–8 °C protected from light; use as soon as practical. Inspect for precipitation, color change, contamination, or dehydration before use.
• Re-heating: Avoid repeated heating/cooling cycles; prepare fresh as needed for critical work.

Notes

• Appearance, pH targets, and exact preparation mass for this specific item are Not specified for this item; refer to CoA/Spec Sheet and SDS for definitive instructions and safety.

Structure and Identity

Item-specific facts (from Product Data)

• Product: MacConkey Broth (SKU M1523321)
• Type: Dehydrated culture medium (complex mixture)
• CAS, CID, InChIKey, SMILES, molecular formula, molecular weight: Not applicable to complex media; Not specified for this item; refer to CoA/Spec Sheet.

General description (literature)

• MacConkey Broth is a selective and differential microbiological medium designed to enrich/detect Gram-negative enteric bacteria and differentiate lactose fermenters via a pH indicator system.
• It is a complex, undefined mixture typically comprising peptones/tryptones (nitrogen source), lactose (carbohydrate), bile salts and crystal violet (selective agents suppressing Gram-positive bacteria), and a pH indicator (commonly neutral red).
• Structural features: As a formulation, it contains multiple classes of compounds (peptides, carbohydrates, dyes, bile salts). No single defined 2D structure exists; instead, the functional components act synergistically to provide selectivity and differentiation.

How to visualize (words)

• Upon dissolution and sterilization, the broth is a clear to slightly opalescent red-tinted aqueous medium (color due to indicator/dye; description is literature). Lactose-fermenting organisms acidify the medium, shifting the indicator toward a deeper red/pink; non-fermenters typically do not acidify, leaving the broth color unchanged or slightly yellow/orange depending on indicator system.

Synthetic Utility

Not applicable to this product category

• MacConkey Broth is a microbiological culture medium and not a reagent for chemical synthesis. It does not serve as a building block, catalyst, or solvent in synthetic chemistry.

Guidance

• For chemical synthesis applications, refer to appropriate solvents, reagents, catalysts, or building blocks. Use this product solely for microbiological culture and differentiation workflows.

Target Specificity

Not applicable to this product category

• Target specificity parameters (antigen/epitope, species reactivity, clone, isotype) apply to antibodies and related affinity reagents and are not relevant to a culture medium. No item-specific data provided.