MacConkey Broth (USP) - BioReagent

Cat. No.: M1528541

GRAU & PUREZA BioReagent

Storage

Room temperature

Shipped In

Normal

Visão geral

For selective enrichment of intestinal bacteria. Preparation method: Weigh 35.0 g of this product in 1 L of distilled or deionized water, heat to boiling until completely dissolved, dispense, autoclave at 121°C for 15 minutes, and set aside for use.

Especificações

Especificações e pureza

BioReagent

Condições de armazenamento de armazenamento

Room temperature

Enviado em

Normal

Grau

BioReagent

Product Line

Produtos biológicos

Application Protocols

Item-specific, validated protocols are not provided in the Product Data. General steps below are literature guidance only; for regulated testing, follow your validated SOPs and the product label/CoA.

General preparation (literature):

• Weigh the manufacturer-specified grams of dehydrated medium per liter. Item-specific g/L: Not specified for this item; refer to CoA/Spec Sheet.
• Dissolve in purified water with stirring. Dispense into tubes/flasks; add Durham tubes if gas detection is needed.
• Sterilize by autoclaving at 121 °C for 15 minutes. Cool to room temperature.

Typical use (literature):

• Inoculate with test sample or enrichment. Incubate at 35–37 °C for 18–24 h.
• Readout: Color change to red/pink indicates acid from lactose fermentation; record gas in Durham tubes if present.
• For confirmation, subculture to MacConkey Agar or other differential/selective plates and perform biochemical identification.

Item-specific recommendations (e.g., volume per tube, control strains, acceptance criteria): Not specified for this item; refer to CoA/Spec Sheet.

Biological Roles

This product itself does not have a biological role within living systems; rather, it is a tool to interrogate microbial physiology in vitro.

Mechanistic/biochemistry context (literature):

• Selective pressure: Bile salts and crystal violet simulate intestinal bile conditions, favoring growth of enteric Gram-negative rods while inhibiting many Gram-positives.
• Carbohydrate fermentation: The presence of lactose enables assessment of β-galactosidase-driven fermentation pathways in Enterobacteriaceae, with acid end-products detected by neutral red (pH indicator), a classic readout of fermentative metabolism.
• Osmotic/ionic balance: Sodium chloride maintains osmotic conditions conducive to enteric growth and indicator performance.

Use implications (literature):

• Differentiates lactose fermenters (e.g., Escherichia, Klebsiella, Enterobacter) from non-fermenters (e.g., Salmonella, Shigella, Proteus) based on acid production in the broth.
• Supports subsequent isolation on MacConkey Agar for colony-level differentiation and confirmation.

No clinical or therapeutic claims are made. This product is for laboratory research and quality-control use only.

Buffer Applications

MacConkey Broth is not formulated or recommended as a chemical buffer system for analytical biochemistry.

• While the prepared medium possesses some buffering capacity inherent to peptones and salts, its composition and dyes can interfere with spectrophotometric or enzymatic assays.
• For buffering needs, choose validated buffers (e.g., phosphate, MOPS, HEPES) tailored to your assay. Use MacConkey Broth strictly for its intended microbiological selective/differential function.

Green Alternatives

While culture media are inherently water-based and relatively benign compared to many organic reagents, environmental considerations still apply.

Greener practice considerations (literature):

• Dehydrated format minimizes transport weight/volume and reduces cold-chain energy vs. ready-to-use liquid media.
• Right-size preparation: Reconstitute only the volume required to minimize disposal of unused sterilized broth.
• Energy-efficient sterilization: Optimize autoclave loads and cycles; avoid over-sterilization that wastes energy and degrades dyes.
• Waste management: Decontaminate spent media (autoclave/validated disinfectant) and segregate from solvent/chemical waste streams. Dyes like crystal violet should be minimized in effluent; treat as per institutional guidance.

Alternative media choices (functional comparison; literature):

• MacConkey Broth vs. Lauryl Sulfate Tryptose (LST) Broth: LST can be used for presumptive coliform testing with potentially simpler dye systems; selection strength differs.
• MacConkey Broth vs. Buffered Peptone Water (BPW): BPW is non-selective and may require follow-up selective steps; it can reduce dye discharge but loses immediate differentiation.
• MacConkey Broth vs. Chromogenic enteric media: Chromogenic substrates can reduce ambiguous readings but may introduce specialty dyes; weigh readability benefits versus dye footprint.

Pharmaceutical Uses

No therapeutic or clinical uses are claimed. In the pharmaceutical and allied industries, MacConkey Broth (USP) serves in quality control microbiology.

• Role (literature): Selective enrichment/detection of bile-tolerant, lactose-fermenting Gram-negative bacteria in compendial testing workflows. Applicable to microbiological quality control of raw materials, intermediates, and finished products where USP chapters specify selective media.
• USP context: The “USP” designation indicates suitability for methods that reference MacConkey Broth in pharmacopeial testing. Always confirm chapter-specific requirements (e.g., USP <61> Microbiological Examination of Nonsterile Products: Microbial Enumeration Tests; USP <62> Tests for Specified Microorganisms) and verify lot conformance via CoA/GPT.
• Validation/qualification: Laboratories should perform suitability/GPT upon receipt or per change control to document that the medium supports growth/inhibition as intended for test organisms in the product matrix (literature best practice).

Documentation: Maintain lot-specific records (CoA, GPT results, preparation logs, sterilization records) to support data integrity in GMP environments.

Physical Properties

Because this is a dehydrated culture medium blend, typical single-compound properties (bp, mp, logP) are not applicable. Key preparation-related properties are provided as general literature guidance.

• Physical form: Dehydrated medium powder or granules (typical for microbiological media). Item-specific appearance: Not specified for this item; refer to CoA/Spec Sheet.
• Solubility: Water-soluble (literature); formulated for dissolution in purified/distilled water prior to sterilization.
• Prepared medium pH: ~7.1 ± 0.2 at 25 °C (literature, typical for MacConkey formulations).
• Color of prepared broth: Reddish/orange due to neutral red (literature).
• Osmolality/ionic strength: Determined by formulation; Not specified for this item; refer to CoA/Spec Sheet.
• Refractive index, density (powder), moisture content: Not specified for this item; refer to CoA/Spec Sheet.

Preparation notes (literature):

• Dissolution in cold water with stirring; avoid overheating indicator-containing media prior to sterilization.
• Sterilize by autoclaving at 121 °C for 15 minutes (literature; verify label directions). Over-sterilization may fade indicator dyes.
• Do not filter-sterilize unless specified, as proteinaceous components can bind filters.

Quality and Grades

• Item grade (from Product Data): BioReagent. This designation indicates suitability for biological and microbiological laboratory workflows, emphasizing formulation consistency, low bioburden in the dehydrated state, and performance in growth-promotion testing.
• Standard: USP in the product name indicates alignment with a United States Pharmacopeia method context for use (e.g., microbiological testing). It typically implies the formulation and performance conform to pharmacopeial expectations for MacConkey Broth used in compendial tests. Always verify lot-specific conformity on the CoA.
• Performance attributes (general for microbiological media):
  • Growth promotion testing (GPT) against specified organisms (e.g., enteric Gram-negatives as positive controls; Gram-positives inhibited) is commonly performed by manufacturers for each lot (literature). Lot-specific pass/fail results: Not specified for this item; refer to CoA/Spec Sheet.
  • pH of prepared medium within specified range at 25 °C (literature). Lot-specific numeric limits: Not specified for this item; refer to CoA/Spec Sheet.
• Stabilizers/antimicrobial preservatives in dehydrated medium: Typically none added; sterility is achieved after reconstitution and autoclaving (literature). Item-specific additives: Not specified for this item; refer to CoA/Spec Sheet.

Recommendation: For regulated testing (e.g., USP/EP/JP microbiological methods), retain lot-specific documentation (CoA, GPT results) with your quality records to demonstrate suitability for intended use (USP <62>, <61>, etc., as applicable).

Reaction and Applications

This section is interpreted for microbiological application rather than chemical reactions.

Typical applications (literature):

• Selective enrichment and detection of Gram-negative enteric bacteria, leveraging bile salts and crystal violet to inhibit Gram-positive organisms.
• Differentiation of lactose fermenters: Organisms fermenting lactose produce acid that shifts the neutral red indicator to pink/red; in broth, acid production can be read as a color change and/or with inverted Durham tubes for gas detection (if used).
• Quality control and compendial testing: Used in USP-aligned microbiological tests where selective enrichment of enterics is required (verify specific chapter requirements for your application).

Mechanistic notes (literature):

• Bile salts + crystal violet disrupt peptidoglycan-associated functions in Gram-positive cells, enhancing selectivity for enteric Gram-negatives.
• Lactose fermentation lowers pH; neutral red transitions to red in acidic conditions, providing differential indication.

Practical tips (literature):

• Verify pH after sterilization; large deviations can change selectivity.
• For enrichment from complex matrices, pre-incubate at 35–37 °C for 18–24 h and subculture to MacConkey Agar for colony isolation.
• Include appropriate positive and negative controls each batch (e.g., E. coli vs. S. aureus) to confirm selectivity and indicator performance.

Reaction Conditions

Interpreted as preparation and incubation conditions for microbiological use (literature guidance; verify label/CoA for lot-specific instructions):

• Reconstitution: Dissolve the labeled mass of dehydrated medium per liter of purified water. Item-specific g/L: Not specified for this item; refer to CoA/Spec Sheet.
• Sterilization: Autoclave at 121 °C for 15 minutes. Avoid prolonged cycles that can degrade lactose and dyes.
• Final pH: Target ~7.1 at 25 °C post-sterilization (typical for MacConkey formulations; verify lot spec).
• Incubation: 35–37 °C for 18–24 hours for enrichment/detection of enteric Gram-negative bacteria.
• Optional Durham tubes: If gas detection is required, place Durham tubes before sterilization; read gas production after incubation (literature practice).
• Controls: Include positive and negative control strains appropriate to your test to verify selectivity and indicator response each batch (literature best practice).

Expected observations (literature):

• Acid production from lactose fermentation results in a red/pink coloration of the broth due to neutral red; non-fermenters do not acidify and remain yellowish to unchanged.

All numeric conditions above are general literature values; follow your validated method and the product’s CoA/label.

Safety and Handling

Safety for complex media should consider both the dehydrated blend and the intended microbiological use.

• GHS classification and hazard statements: Not specified for this item; refer to SDS. Many dehydrated media are not classified as hazardous, but components such as crystal violet and neutral red may present irritation or environmental hazards in concentrated form (literature). Always consult the SDS.
• Primary risks during use: Potential exposure to viable microorganisms cultured in the medium. Implement appropriate biosafety practices (e.g., BSL-1/2 as applicable) and treat used media as biohazardous waste.
• PPE: Laboratory coat, gloves, and safety glasses; wear a dust mask or handle in a fume hood if creating dust/aerosols during weighing (general lab practice).
• Handling: Avoid dust formation. Do not ingest. Prevent contact with eyes/skin. Clean spills with damp methods to avoid dust.
• Incompatibilities: Strong oxidizers/detergents can degrade organic components and indicator dyes; avoid mixing with disinfectants except for surface decontamination of spills.
• First aid (overview; defer to SDS): Rinse eyes/skin with water upon contact; if inhaled, move to fresh air; if ingested, rinse mouth. Seek medical advice if symptoms persist.
• Sterilization/decontamination: Autoclave used media and cultures before disposal; use appropriate disinfectants (e.g., 10% bleach) where autoclaving is not immediately available.

Definitive hazard classification and transport information: Not specified for this item; refer to SDS and CoA/Spec Sheet.

Solvent Selection

This product is not a solvent; it is a dehydrated culture medium formulated for reconstitution in water.

• Reconstitution medium: Purified/distilled/deionized water (literature). Avoid high ionic strength or buffered waters that can alter selectivity/indicator performance.
• Polarity/miscibility: Not applicable. The blend is designed to dissolve/disperse completely in water to form a clear to slightly opalescent broth (literature).
• Practical notes (literature):
  • Use high-purity water with low TOC and minimal residual disinfectants (e.g., chlorine/chloramine) that may bleach indicator dyes.
  • Heat gently only as needed for dissolution; excessive heating before autoclaving can degrade lactose and dyes.

When to choose MacConkey Broth vs alternatives (literature):

• Choose MacConkey Broth for enrichment/detection of bile-tolerant, lactose-fermenting Gram-negative enterics with a color/acid indicator system.
• Consider Violet Red Bile Broth/Agar for coliform counts in foods; Lauryl Sulfate Tryptose Broth for presumptive coliform testing; MacConkey Agar for differential plating when colony morphology is needed.

Storage and Reconstitution

• Storage conditions (from Product Data): Room temperature for the dehydrated medium. Protect from moisture, heat, and light to preserve indicator dyes and prevent clumping.
• Shipping (from Product Data): Normal.
• Container management: Keep tightly sealed with desiccant if provided. Avoid humid environments; re-close promptly after use.

Reconstitution (general, literature):

• Dissolve the label-specified mass per liter of purified water with stirring. Do not provide heat beyond what is necessary for dissolution. Item-specific g/L: Not specified for this item; refer to CoA/Spec Sheet.
• Sterilize by autoclaving at 121 °C for 15 minutes unless otherwise specified on the label.
• After sterilization, cool and, if not used immediately, store prepared broth at 2–8 °C and use within a time window justified by your lab’s media QC program (literature). Exact shelf life: Not specified for this item; refer to CoA/Spec Sheet.

Freeze–thaw guidance: Not applicable to dehydrated media. Avoid freezing prepared broth unless validated, as freeze–thaw can precipitate components and affect indicator performance.

Research use note (from Product Data): For research use only.

Structure and Identity

This product is a complex, dehydrated microbiological culture medium rather than a single defined chemical compound. As such, single-molecule identifiers do not apply.

• Product type: Selective and differential culture medium (MacConkey Broth, USP) for Gram-negative, lactose-fermenting enterics
• Composition (literature, typical for MacConkey media): peptones/enzymatic digests (nitrogen source), lactose (fermentable carbohydrate), bile salts and/or oxgall (selective agent), crystal violet (additional selectivity), sodium chloride (ionic balance), and neutral red (pH indicator). Exact formulation may vary by manufacturer/specification.
• Molecular formula: Not applicable to a mixture
• Molecular weight: Not applicable to a mixture
• SMILES / InChI / InChIKey: Not applicable to a mixture
• Structural features: Heterogeneous blend of organic and inorganic constituents; includes indicator dye (neutral red) and selective agents (bile salts, crystal violet) in a protein hydrolysate matrix with carbohydrate.

Item-specific identifiers and quantitative composition: Not specified for this item; refer to CoA/Spec Sheet.

Synthetic Utility

Not applicable. This product is a complex culture medium and is not used as a reagent or building block in chemical synthesis.

For chemical synthesis tasks, refer to dedicated reagents/solvents. For this product, see the sections on Reaction & Applications (microbiology), Pharmaceutical Uses, and Application Protocols for relevant guidance.

Target Specificity

This section applies to antibody/bioreagent targeting information and does not apply to a microbiological culture medium.

• Target/antigen/clone/isotype: Not applicable to this product type.
• Item-specific target data: Not specified for this item; refer to CoA/Spec Sheet.

Perguntas frequentes

How should this product be stored?

Store at room temperature.