MacConkey Liquid Medium (ChP) - BioReagent

Cat. No.: M1528476

등급 & 순도 BioReagent

Storage

Room temperature

Shipped In

Normal

개요

For selective enrichment of Escherichia coli

사양

사양 및 순도

BioReagent

보관 조건

Room temperature

배송

Normal

등급

BioReagent

Product Line

생물 제품

Application Protocols

General research protocol example (literature; adapt to your SOP and strain/matrix):

1. Preparation

• If supplied sterile and ready-to-use, inspect the bottle for clarity, color, and integrity. Do not use if contaminated or precipitated. Item-specific preparation is Not specified for this item; refer to CoA/Spec Sheet.

2. Inoculation

• Aseptically transfer a defined volume of sample or standardized inoculum into the medium. Include:
  • Negative control: uninoculated medium.
  • Positive controls: lactose-positive (e.g., Escherichia coli) and lactose-negative (e.g., Salmonella enterica) strains.

3. Incubation

• 35–37 °C for 18–24 h under aerobic conditions (typical for enterics). Do not shake excessively if working with surface films; moderate agitation can improve oxygenation for some strains.

4. Interpretation

• Growth: Turbidity indicates proliferation.
• Lactose fermentation: Acid production yields a neutral red color shift (broth becomes red/pink). Lack of color change suggests non-lactose fermentation under these conditions.

5. Follow-up

• Subculture to MacConkey agar or other differential/confirmatory media. Perform biochemical or molecular identification as required by your study.

Note: Sterility, pH, and indicator performance should be verified periodically. For regulated work, perform growth-promotion/selectivity testing on each lot.

Biological Roles

MacConkey Liquid Medium exploits physiological traits of enteric bacteria to achieve selectivity and differentiation (literature context):

• Bile tolerance: Many Gram-negative enterics are adapted to bile salts encountered in the intestinal environment. Inclusion of bile salts suppresses Gram-positive flora, enriching for bile-tolerant Gram-negative rods.
• Crystal violet sensitivity: Crystal violet further inhibits Gram-positive cell wall biosynthesis, sharpening selectivity against cocci and certain Gram-positives.
• Carbohydrate fermentation: Lactose serves as a fermentable carbohydrate. Organisms possessing β-galactosidase and the lactose permease system metabolize lactose to organic acids.
• pH indicator response: Neutral red is a pH indicator that turns red/pink in acidic conditions. In liquid MacConkey medium, acidification from lactose fermentation produces a measurable color change in the broth.
• Osmotic balance and growth support: Electrolytes (e.g., sodium chloride) maintain osmotic pressure; peptones/tryptones provide amino acids, peptides, vitamins, and growth factors.

These design elements collectively favor the recovery and differentiation of lactose-fermenting enterics (e.g., many Escherichia and Klebsiella spp.) from non-lactose fermenters (e.g., Salmonella, Shigella), aiding researchers in enrichment, preliminary discrimination, and downstream confirmation using biochemical or molecular methods.

Note: The above describes general biological principles of MacConkey media and is provided for research context; it is not item-specific composition.

Buffer Applications

This product is a complex selective/differential culture medium and is not intended to serve as a buffering reagent for biochemistry workflows.

• While MacConkey media contain components that confer some buffering capacity (literature: phosphates or peptone matrices can temper pH shifts), their formulation is optimized for microbial selectivity and indicator performance rather than precise buffering at a defined pH.
• For controlled pH experiments or protein work, select a dedicated buffer system (e.g., phosphate, HEPES, MOPS) with defined pKa and ionic strength.

If pH control is critical in your microbiological study, validate that any external buffering or pH adjustments do not interfere with lactose fermentation signaling or the selectivity of the medium.

Green Alternatives

While culture media are aqueous and generally benign compared to organic solvent–heavy workflows, MacConkey formulations typically contain dyes (e.g., crystal violet, neutral red) that warrant mindful handling and disposal.

Greener practice considerations (general, literature):

• Minimize dye exposure and waste: Use only the volumes needed per run; consolidate partially used bottles when permissible and within sterility limits.
• Light protection extends life: Protect from light to reduce indicator degradation, lowering waste from premature discard.
• Sterile reusables: Where allowed by your quality system, use sterilizable glassware instead of single-use plastics for transfers to reduce plastic waste.
• Validated neutralization/disposal: Deactivate biological loads prior to disposal (autoclave or approved disinfectant), and segregate dye-containing waste per local regulations to prevent aquatic discharge.

Alternative media (tradeoffs; literature):

• Chromogenic media can offer clearer differentiation with potentially different dye systems; evaluate toxicity/ecotoxicity of chromogens and cost versus MacConkey.
• Bile salt–free enrichment broths reduce selective chemical load but may increase non-target growth, requiring more downstream work.

Summary: The principal environmental lever with MacConkey Liquid Medium is responsible use, minimizing dye-containing waste streams, and adopting reusable materials where feasible without compromising sterility or data integrity.

Pharmaceutical Uses

No therapeutic use. For research use only.

Contextual laboratory/industrial roles (literature; non-clinical):

• Microbiological quality investigations: MacConkey media are commonly employed in laboratories supporting pharmaceutical, bioprocess, and environmental monitoring research to enrich and differentiate Gram-negative enterics from mixed samples.
• Method development and suitability testing: Useful in developing and qualifying microbiological methods where selective enrichment of bile-tolerant Gram-negative bacteria is desired before confirmatory identification.
• Utilities and raw material studies: Evaluation of water systems or raw material bioburden in R&D settings when enteric contaminants are of interest.

Regulatory note:

• The “(ChP)” designation indicates alignment with Chinese Pharmacopoeia concepts for medium performance. However, suitability for a specific compendial or GMP application must be established by the end user through growth-promotion, selectivity, and inhibitory testing as dictated by the applicable guidelines. Refer to the product CoA/Spec Sheet for available performance data.

Physical Properties

As a ready-to-use liquid microbiological medium, MacConkey Liquid Medium is an aqueous solution containing complex organic and inorganic components. Item-specific physicochemical constants are not defined as for a pure substance.

• Appearance: Not specified for this item; refer to CoA/Spec Sheet.
• pH (working pH): Typical MacConkey formulations are adjusted to approximately pH 7.1 at 25 °C (literature). Exact pH for this item: Not specified; refer to CoA/Spec Sheet.
• Density, refractive index, viscosity: Not specified for this item; refer to CoA/Spec Sheet. For context, values are generally close to water for dilute aqueous media (literature, general observation).
• Boiling/Melting point: Not applicable as a formulated aqueous medium; dominated by water behavior (literature).
• Solubility: Fully aqueous; miscible with water (general). Not intended to be mixed with organic solvents.
• Osmolality/tonicity: Not specified for this item; refer to CoA/Spec Sheet (literature: MacConkey media include electrolytes to maintain osmotic balance for enterics).
• Color: Typically light red/orange due to neutral red and crystal violet in solution (literature). Exact hue/intensity can vary; Not specified for this item.

Handling notes (general):

• pH and indicator color can shift with CO2 absorption or prolonged exposure to light/heat (literature). Protect from strong light and tightly cap to minimize CO2 uptake. Always verify sterility and clarity before use.

Quality and Grades

• Grade/Purity (item-specific): BioReagent. Indicates suitability for laboratory biological research applications, prepared with reagents and processes aimed at consistent microbiological performance. Not a clinical diagnostic product.
• ChP designation (item-specific): The name includes “(ChP),” indicating the formulation is designed to align with Chinese Pharmacopoeia expectations for MacConkey medium performance (e.g., selectivity and growth promotion characteristics). Users should verify compliance for their regulated workflows by reviewing the CoA/Spec Sheet and performing in-house suitability tests as required.
• Appearance, performance specs (selectivity/differential responses): Not specified for this item; refer to CoA/Spec Sheet.

What BioReagent means in practice:

• Raw materials control: Microbiology-grade peptones, carbohydrates, salts, and indicators targeted to provide batch-to-batch consistency (general practice).
• Microbiological performance: Each lot is typically qualified using growth-promotion/selectivity tests (literature standard for culture media). Specific challenge strains and acceptance criteria for this item are not specified; refer to CoA/Spec Sheet.

Stabilizers/Preservatives:

• Not specified for this item; refer to CoA/Spec Sheet. Some ready-to-use liquids may include preservatives or pH stabilizers; verify if relevant to your assay.

Documentation recommendations:

• Retain lot CoA and, for regulated labs, conduct compendial suitability testing (e.g., growth-promotion) under your quality system to confirm performance in your methods.

Reaction and Applications

This section is interpreted for microbiological applications rather than chemical reactions, as MacConkey Liquid Medium is a culture medium.

Use cases (research and lab QA/QC, literature):

• Selective enrichment of Gram-negative enteric bacteria from mixed samples (environmental, food, industrial water), leveraging bile salts and crystal violet to suppress most Gram-positive organisms.
• Differential detection of lactose fermentation: lactose-positive organisms acidify the medium, causing a neutral red indicator color shift; lactose-negative organisms do not produce the same acidification pattern.
• Pre-enrichment prior to plating on solid selective media (e.g., MacConkey agar) to increase recovery of stressed or low-abundance enterics.

Practical tips (general, literature):

• Inoculation: Aseptically inoculate directly into the liquid. For quantitative studies, use defined inoculum volumes and include uninoculated controls.
• Incubation: 35–37 °C for 18–24 h is typical for Enterobacteriaceae recovery; optimize temperature/time for target organisms.
• Controls: Include a lactose-positive control strain (e.g., Escherichia coli) and a lactose-negative control (e.g., Salmonella enterica serovar Typhimurium) to verify differential response.
• Interpretation: Observe turbidity for growth and indicator color change for lactose fermentation. Confirm findings by streaking to differential/confirmatory agar or by biochemical tests as appropriate.

Note: This product is for research use only. For regulated testing, perform method suitability/growth-promotion tests to verify performance with your strains and matrices.

Reaction Conditions

Not applicable to chemical reactions.

Microbiological incubation guidance (literature, general):

• Temperature: Commonly 35–37 °C for enteric bacteria; adjust based on the organism under study.
• Time: 18–24 h is typical for observing growth and lactose fermentation signals in broth; extended incubation may be used for slow growers, with appropriate controls.
• Atmosphere: Aerobic incubation is standard; some facultative anaerobes will also grow under reduced oxygen.
• Inoculum: Standardize inoculum size to ensure reproducibility and avoid overloading selective capacity.
• Readouts: Monitor turbidity and neutral red color change; confirm by subculture to differential agar or biochemical assays.

Item-specific incubation parameters, if any, are Not specified for this item; refer to CoA/Spec Sheet. Always validate conditions for your strains and sample matrices.

Safety and Handling

This product is an aqueous culture medium containing selective agents and dyes. While generally low hazard under normal laboratory use, components such as crystal violet, bile salts, and neutral red can pose irritation and staining risks.

• GHS classification, signal word, H-statements, pictograms: Not specified for this item; refer to the SDS for authoritative hazard information.
• Primary hazards (general, literature):
  • Crystal violet and neutral red are biologically active dyes; avoid ingestion, inhalation of aerosols, and skin/eye contact.
  • Bile salts can irritate skin/eyes and mucous membranes.
  • Microbiological risk: once inoculated, the medium will contain viable organisms—handle as biohazard per your institutional biosafety level (BSL) procedures.
• PPE: Laboratory coat, gloves (nitrile), and eye protection. Use a biological safety cabinet for handling pathogenic organisms as required by your biosafety protocol.
• Incompatibilities: Avoid mixing with strong oxidizers and strong acids/bases that can degrade indicator dyes and peptides (general). Do not autoclave containers tightly sealed if heating unopened—vent as appropriate to prevent pressure buildup.
• First aid (overview):
  • Skin: Wash with soap and water. Remove contaminated clothing.
  • Eyes: Rinse cautiously with water for several minutes; remove contact lenses if present and easy.
  • Inhalation: Move to fresh air; seek medical attention if symptoms persist.
  • Ingestion: Rinse mouth; seek medical attention.
• Spill/cleanup: Absorb with inert material, wash area with water/detergent. Disinfect if spill involves inoculated medium.

Always consult the product SDS and your institutional biosafety guidelines before use.

Solvent Selection

Not applicable as a solvent. MacConkey Liquid Medium is an aqueous culture medium intended to be used as supplied for microbiological cultivation.

Practical guidance (general):

• Matrix compatibility: Use as-is for inoculation of test organisms or samples. If concentration/filtration steps are required in your method, validate that any diluents or neutralizers are compatible with selective/differential functions of the medium.
• Sterility considerations: Maintain sterility during transfer. If the product is supplied sterile, avoid introducing solvents or additives that could compromise selectivity (e.g., alcohols, strong surfactants) unless validated for your application.
• Alternative formulations: If organic solvent tolerance is required (e.g., extract testing), consider parallel controls to assess any solvent impact on indicator response or organism recovery.

Storage and Reconstitution

• Storage conditions (item-specific): Room temperature (per Product Data). Maintain in original, tightly closed container.
• Shipping: Normal (per Product Data).
• Reconstitution: Not applicable for a liquid ready-to-use medium unless supplied as a concentrate. Item-specific details are Not specified for this item; refer to CoA/Spec Sheet.
• Light protection: Store away from direct light to preserve indicator dyes (literature best practice).
• Aseptic handling: Minimize open time and headspace exposure. Flame-sterilize bottle necks where appropriate, or use sterile connectors.
• Freeze–thaw: Avoid freezing unless the product documentation explicitly allows it; freezing may precipitate components and impair performance (general guidance).
• Shelf life/expiry: Not specified for this item; refer to CoA/Spec Sheet. Do not use beyond expiry.
• Post-use: If container becomes contaminated, discard per biohazard procedures. Decontaminate inoculated media by autoclaving or with validated disinfectants prior to disposal.

Always consult the product label and CoA/SDS for lot-specific storage and handling instructions.

Structure and Identity

MacConkey Liquid Medium (ChP) is a complex, undefined microbiological growth medium formulated for the selective enrichment and differential cultivation of Gram-negative enteric bacteria via lactose fermentation.

• Product type: Complex liquid culture medium (selective and differential)
• Composition: Complex mixture (peptones/tryptones, salts, indicators, selective agents). Exact lot-specific composition and concentrations are proprietary and may vary within specification.
• ChP designation: Prepared to align with Chinese Pharmacopoeia (ChP) requirements for MacConkey medium performance (see Quality & Grades). Not a single chemical entity.
• Molecular formula: Not applicable to complex media.
• Molecular weight: Not applicable to complex media.
• CAS, CID, InChIKey, SMILES: Not applicable for mixtures of undefined composition; Not specified for this item; refer to CoA/Spec Sheet.
• Structural features: Not a discrete molecule; contains typical functional classes (proteins/peptides hydrolysates, carbohydrates, dyes, bile salts) rather than a single 2D structure.

Typical functional components (literature, for context; not item specifications):

• Peptone/tryptone (nitrogen/carbon source)
• Lactose (fermentable carbohydrate for differentiation)
• Bile salts and crystal violet (selective agents suppressing most Gram-positive bacteria)
• Neutral red (pH indicator for acid from lactose fermentation)
• Electrolytes (e.g., NaCl) (osmotic balance)

Note: Refer to the product CoA/Spec Sheet for exact lot-specific identity tests and composition ranges.

Synthetic Utility

Not applicable. MacConkey Liquid Medium (ChP) is a microbiological culture medium and is not used as a synthetic reagent or building block in chemical synthesis.

For workflows requiring selective enrichment prior to chemical analysis (e.g., metabolomics or endotoxin studies), this medium may be used upstream of analytical chemistry steps, but it does not itself participate in or promote chemical reactions in the synthetic sense.

Target Specificity

This section is intended for biologics (e.g., antibodies) and does not apply to a culture medium.

• No antigen/epitope, clone, isotype, or species reactivity is associated with this product.
• For organism selectivity, see Reaction & Applications and Biological Roles for literature-based descriptions of how the medium enriches Gram-negative enterics and differentiates lactose fermenters.