MacConkey Agar - BioReagent

Cat. No.: M1528354

QUALITÀ & PUREZZA BioReagent

Storage

Room temperature

Shipped In

Normal

Panoramica

For selective isolation of intestinal pathogens

Specifiche

Specifiche e purezza

BioReagent

Condizioni di conservazione di stoccaggio

Room temperature

Spedito in

Normal

Grado

BioReagent

Product Line

Prodotti biologici

Application Protocols

Note: The following is general, literature‑based guidance for MacConkey Agar and not item‑specific instructions. Always verify against your CoA/Spec Sheet and lab SOPs.

• Plate preparation (literature)

  • Weigh the dehydrated medium according to the manufacturer’s recommended grams per liter; suspend in purified water with stirring and heat to dissolve.
  • Autoclave (e.g., 121 °C, ~15 min). Cool to 45–50 °C, mix gently to avoid bubbles, and pour into sterile Petri dishes (typically 20–25 mL per 90‑mm plate). Allow to solidify and dry surface before use.

• Quality control (literature examples)

  • Positive control (lactose fermenter): Escherichia coli — expect pink to red colonies with surrounding bile precipitate.
  • Negative control (non‑fermenter): Salmonella enterica or Shigella spp. — expect colorless or pale colonies.
  • Inhibition control: A Gram‑positive organism (e.g., Staphylococcus aureus) shows poor or no growth.

• Inoculation and incubation (literature)

  • Streak for isolation using aseptic technique. Incubate plates inverted at 35–37 °C for 18–24 h. Examine for colony color and morphology.

• Disposal

  • Autoclave used plates and cultures prior to disposal as biohazardous waste.

Biological Roles

MacConkey Agar itself is not a biological macromolecule but serves as a functional microenvironment to probe microbial physiology.

• Functional biology (literature)

  • Selectivity: Bile salts and crystal violet mimic inhibitory components encountered in the gut and suppress many Gram‑positive organisms, enriching for Gram‑negative enterics.
  • Differential metabolism: Lactose plus neutral red reveals fermentation status. Acid from lactose fermentation lowers local pH, turning neutral red to pink/red and causing bile precipitation around colonies.
  • Osmotic/ionic balance: Sodium chloride maintains osmotic equilibrium to support typical colony morphology.
  • Nutritional support: Peptones provide amino acids, peptides, and nitrogen sources; agar provides a non‑metabolizable solid support enabling isolation of discrete colonies.

• Use in microbial ecology and genetics

  • Enables selection and phenotypic screening of mutants affecting carbohydrate utilization, transport, or acid tolerance.
  • Facilitates enumeration of coliforms as indicators of fecal contamination in environmental microbiology research.

Note: All uses are for research or quality‑control laboratory purposes; no clinical diagnostic use is implied here.

Buffer Applications

MacConkey Agar is not a buffering reagent and is not typically used to prepare defined buffer systems. While prepared media exhibit a formulated pH and some intrinsic buffering from peptones and salts, this product is intended as a selective/differential growth medium rather than a buffer.

• For buffer needs, select defined systems (e.g., phosphate, Tris, HEPES) appropriate to your application.

Green Alternatives

Because MacConkey Agar is an aqueous, agar‑based medium, traditional “green solvent” substitution is not directly applicable. Nonetheless, sustainability and safety can be improved through process choices.

• Considerations and options (general/literature)

  • Use energy‑efficient autoclave cycles and load consolidation to reduce steam and power consumption during sterilization.
  • Adopt reusable glassware (e.g., glass Petri dishes) where appropriate to reduce single‑use plastics; balance with contamination risk and cleaning validation needs.
  • Evaluate alternative selective/differential media that reduce hazardous dye content (e.g., chromogenic media with lower mass of classical dyes), noting performance tradeoffs and cost.
  • Right‑size batch preparation to minimize expired/unused plates and waste.

• Tradeoffs

  • Pre‑prepared plates reduce in‑lab energy/water use but increase shipping footprint and packaging waste; dehydrated media shift energy use to the point of preparation but allow just‑in‑time batching.
  • Some alternatives (e.g., EMB agar) use different dye systems with their own environmental profiles; choose based on performance needs and waste management capabilities.

Pharmaceutical Uses

No therapeutic use. In pharmaceutical and biomanufacturing laboratories, MacConkey Agar is used in microbiology quality control and environmental monitoring workflows (research/QC use only).

• Typical roles (literature/general)

  • Recovery and differentiation of Gram‑negative, lactose‑fermenting vs. non‑fermenting organisms from surfaces, utilities, and process samples.
  • Investigation of bioburden composition in raw materials and process intermediates where selective enumeration of enteric Gram‑negatives is informative.
  • Method suitability and growth‑promotion testing as part of compendial microbiology (when specified by method or internal SOPs). Ensure the specific formulation aligns with the governing pharmacopeial or method requirements.

• Practical considerations

  • Document media lot, preparation date, sterilization parameters, and plate QC results (e.g., recovery of control strains) per GMP/GLP documentation practices.
  • Use in conjunction with non‑selective media to assess total bioburden vs. selective recoveries.

Physical Properties

• Item-specific physical data

  • Appearance: Not specified for this item; refer to CoA/Spec Sheet.
  • Any numeric specifications (BP/MP/density/RI/UV cutoff, etc.): Not specified for this item; refer to CoA/Spec Sheet.

• General/literature properties for MacConkey Agar (dehydrated medium)

  • Physical form: Free‑flowing, heterogeneous dehydrated powder; yields a firm gel when prepared with water and sterilized (literature).
  • Solubility: Readily dispersible in purified/distilled water; components dissolve/swell upon heating (literature).
  • Color: Tan to pinkish powder; prepared plates typically pale red due to neutral red (literature; color can vary by manufacturer and lot).
  • Gel matrix: Agar provides thermoreversible gelation; typical gelation on cooling from ~100 °C to ~40–45 °C (literature, agar property).
  • pH of prepared medium: Commonly near neutral/slightly acidic as formulated; exact pH targets are manufacturer‑specific (literature; check CoA).

Notes

• Because this product is a mixture, conventional single‑compound descriptors (molecular weight, SMILES, logP, refractive index) are not applicable. Use the item’s CoA/Spec Sheet for any lot‑specific preparation and pH targets.

Quality and Grades

• Item-specific grade

  • Grade/Purity: BioReagent (per Product Data).

• What BioReagent grade typically implies (general)

  • Suitable for laboratory research applications, including routine microbiology and teaching/research culture work.
  • Emphasis on consistent performance characteristics rather than ultra‑trace chemical purity; for culture media, this commonly includes growth‑promotion and selectivity testing against defined control strains (e.g., lactose‑fermenting and non‑fermenting Enterobacterales) — note: actual lot testing parameters are manufacturer‑specific; consult the CoA.
  • Low bioburden in the dehydrated powder and controlled levels of inhibitory contaminants to ensure reproducible colony morphology and color development.

• Stabilizers and formulation notes

  • MacConkey Agar contains functional components (bile salts, crystal violet, neutral red) whose proportions control selectivity/differentiation. Exact composition, indicator concentration, and target pH are formulation‑specific; refer to the Spec Sheet for this item.

• Practical guidance

  • Verify lot-specific performance via in‑house quality control (e.g., recovery and color reactions of ATCC control strains) when media are used in regulated workflows.
  • For analytical or regulated testing (food/water/pharma QC), align with compendial or method‑specified formulations where applicable and document equivalency.

Reaction and Applications

This product is a microbiological culture medium, not a reagent for chemical reactions. Relevant applications pertain to microbial isolation and differentiation.

• Core applications (literature/general)

  • Selective isolation of Gram‑negative enteric bacilli from mixed samples (e.g., environmental, food, clinical research specimens) via inhibition of many Gram‑positives by bile salts and crystal violet.
  • Differential identification of lactose fermenters (e.g., Escherichia coli, Klebsiella spp.) producing pink to red colonies with precipitated bile vs. non‑fermenters (e.g., Salmonella, Shigella) forming colorless/pale colonies.
  • Enumeration of coliforms and assessment of sanitation indicators in water and food microbiology research (per established methods; choose compendial variants as required).

• Practical tips

  • Prepare plates to a uniform thickness; excessive depth can alter colony size and color development.
  • Dry plates before use to eliminate surface moisture that may cause swarming or color diffusion.
  • Incubate aerobically at temperatures consistent with target organisms (often 35–37 °C for enterics; literature) and examine at 18–24 h, with re‑inspection at 48 h if needed.
  • For lactose‑late fermenters, consider parallel plating on a non‑selective medium to confirm viability and aid interpretation.

Reaction Conditions

Chemical reaction conditions are not applicable. For microbiological culture, the following preparation/incubation parameters are commonly cited in the literature (general guidance; not item-specific specifications):

• Preparation (literature)

  • Disperse the dehydrated medium in purified water with heating and agitation until fully dissolved; avoid scorching.
  • Sterilize by autoclaving (e.g., 121 °C for ~15 minutes; literature standard). Cool to ~45–50 °C before pouring plates to minimize condensation.
  • Optional supplements (e.g., antibiotics) should be sterile‑filtered and added after cooling to prevent degradation.

• Incubation (literature)

  • Aerobic incubation typically 35–37 °C for 18–24 h for enteric bacteria; examine for characteristic colony color/morphology.
  • Extended incubation up to 48 h may be used for slow growers; avoid excessive incubation that can lead to dye diffusion or overgrowth.

Always follow your laboratory SOPs and consult the product’s CoA/Spec Sheet for any required, item‑specific preparation parameters.

Safety and Handling

• GHS classification and hazards (item-specific)

  • Signal Word: Not specified for this item; refer to SDS.
  • Hazard Statements (H‑Statements): Not specified for this item; refer to SDS.
  • GHS Pictograms/Classification: Not specified for this item; refer to SDS.

• General safety considerations (mixture; literature/best practice)

  • While dehydrated MacConkey Agar is typically considered of low inherent chemical hazard, it contains dyes (e.g., crystal violet, neutral red) that can stain and may be harmful if ingested or upon prolonged contact. Avoid inhalation of dust and contact with eyes/skin.
  • Microbiological risk dominates in use: once inoculated/incubated, plates and broths contain live microorganisms. Treat all used media as biohazardous waste and autoclave before disposal.
  • Incompatibilities: Avoid strong oxidizers with organic dyes and peptones. Keep dry; moisture uptake can cause clumping and performance variability.

• PPE and handling

  • Wear lab coat, gloves, and safety glasses; use a dust mask or work in a clean area if handling bulk powder to minimize inhalation of particulates.
  • Use aseptic technique when preparing and pouring plates; sterilize equipment and work near a flame or in a biosafety cabinet as appropriate.

• First aid (overview; defer to SDS)

  • Inhalation: Move to fresh air; seek medical attention if irritation persists.
  • Skin/eye contact: Rinse with water for several minutes; remove contaminated clothing; seek medical advice if irritation continues.
  • Ingestion: Rinse mouth; do not induce vomiting; obtain medical assistance.

Always consult the product’s SDS for authoritative safety and regulatory information.

Solvent Selection

Not a solvent. For preparation, purified or distilled water is the appropriate diluent for reconstitution of dehydrated MacConkey Agar.

• General guidance (literature)

  • Use high‑quality water (e.g., ASTM Type II or better) to minimize variability from ions/organics.
  • Heat with agitation to fully dissolve/disperse the powder before sterilization.
  • Do not use organic solvents; the medium is designed for aqueous preparation only.

• Comparison to alternatives

  • Prepared media (pre‑poured plates) offer convenience but shorter shelf life; dehydrated media provide flexibility and longer storage.
  • Selective/differential function is intrinsic to the formulation rather than the solvent.

Storage and Reconstitution

• Item-specific storage

  • Storage Conditions: Room temperature (per Product Data). Keep container tightly closed in a dry place. Protect from humidity and direct light to preserve dye integrity.
  • Shipped In: Normal (per Product Data).

• Reconstitution and use (general/literature)

  • Reconstitute in purified/distilled water with heating and agitation until fully dissolved; avoid localized overheating.
  • Sterilize by autoclaving prior to pouring plates or preparing deep tubes. Allow to cool to ~45–50 °C before dispensing to avoid excessive condensation and to enable optional sterile additives.
  • Label with preparation date and lot; store prepared plates at 2–8 °C in the dark, sealed to prevent desiccation (literature practice). Monitor for dehydration, contamination, or color shift before use.

• Stability

  • Dehydrated media are generally stable at ambient temperature when kept dry and sealed. Opened containers should be promptly resealed; consider desiccant use. For definitive shelf life and lot‑specific guidance, consult the CoA/Spec Sheet.

• Research Use Note

  • For research use only (per Product Data).

Structure and Identity

MacConkey Agar is a complex, undefined microbiological growth medium formulated for the isolation and differentiation of Gram‑negative enteric bacteria. It is a dehydrated mixture; it is not a single, well‑defined chemical compound.

• Item-specific identifiers

  • CAS: Not specified for this item; refer to CoA/Spec Sheet.
  • Molecular Formula: Not specified for this item; refer to CoA/Spec Sheet.
  • Molecular Weight: Not specified for this item; refer to CoA/Spec Sheet.
  • SMILES: Not applicable (mixture).
  • InChIKey: Not applicable (mixture).
  • CID: Not applicable (mixture).

• Typical compositional features (literature/general knowledge)

  • Contains enzymatic digests of casein and animal tissues (peptones), sodium chloride, bile salts, lactose, the pH indicator neutral red, and trace crystal violet, solidified with agar (literature).
  • Designed as a selective (bile salts/crystal violet inhibit most Gram‑positives) and differential (lactose fermentation detected by neutral red) medium.

• Structural description in words (mixture)

  • Heterogeneous blend of biopolymers (agar polysaccharides), small‑molecule dyes (neutral red, crystal violet), carbohydrates (lactose), inorganic salts (NaCl), and complex peptides. No single 2D structure applies.

Synthetic Utility

Not a synthetic organic reagent. MacConkey Agar has no role in chemical synthesis, catalysis, or building‑block transformations.

• For users seeking functionalized agar or polysaccharide matrices for chemical applications (e.g., immobilization), choose chemically defined agars or agaroses rather than selective microbiological media containing dyes and bile salts.

Target Specificity

Not an antibody or molecular probe. Target specificity in this context refers to selective growth of organisms.

• Functional selectivity (literature)
  • Inhibits many Gram‑positive bacteria via bile salts and crystal violet.
  • Differentiates lactose‑fermenting vs. non‑fermenting Gram‑negative bacilli using neutral red indicator and lactose as a substrate.

No clone, isotype, antigen, or species‑reactivity data apply.

Domande frequenti

How should this product be stored?

Store at room temperature.