M17 Agar - BioReagent

Cat. No.: M1528709

GRADE & PURITY BioReagent

Storage

Room temperature

Shipped In

Normal

Overview

For detection of lactic acid bacteria in milk and dairy products, and for isolation of phage-infected lactic acid bacteria

Specifications

Specifications & Purity

BioReagent

Storage

Room temperature

Shipped In

Normal

Grade

BioReagent

Product Line

biological_products

Application Protocols

The following procedures provide general, literature-based guidance for laboratory use. Always adapt to your SOP and the instructions on the product label.

• Preparation of M17 Agar plates (1 L batch):
  1. Weigh the quantity of dehydrated M17 Agar specified on the label (g/L). Suspend in ~900 mL purified water with stirring.
  2. Heat to dissolve completely. Adjust pH near neutral if required by your method.
  3. Bring to 1 L with purified water. Dispense into an autoclavable bottle; cap loosely.
  4. Autoclave at 121 °C for 15 min. Allow to cool to 45–50 °C.
  5. Aseptically add sterile-filtered heat-labile supplements (e.g., carbohydrates, antibiotics, indicators) if used. Mix gently.
  6. Pour 20–25 mL per sterile Petri dish. Let solidify; dry if needed. Store plates inverted at 2–8 °C in sealed sleeves.
• Inoculation and incubation (lactic streptococci; literature):
  • Streak or spread 100 µL of appropriately diluted sample. Incubate at ~30 °C for 24–48 h. Consider microaerophilic or anaerobic jars for some LAB to enhance recovery.
• Quality checks:
  • Perform growth promotion testing with representative strains (e.g., lactic streptococci) and sterility checks (uninoculated controls). Record colony counts (CFU), morphology, and any atypical background growth.
• Disposal:
  • Autoclave used plates and media before disposal per biosafety and institutional guidelines.

Note: Volumes, temperatures, and timings above are general guidance, not item-specific specifications.

Biological Roles

As a complex culture medium, M17 Agar does not have a single defined biological role; rather, it provides a physicochemical environment that supports microbial growth. The following are general literature-based roles of its functional components:

• Nutrient provision (literature):
  • Peptones and yeast extracts furnish amino acids, peptides, nucleotides, vitamins (e.g., B-complex), and trace minerals, satisfying biosynthetic demands of lactic acid bacteria.
• pH stabilization (literature):
  • Phosphate species (often including β-glycerophosphate in M17 formulations) buffer metabolic acidification from lactic acid production, helping maintain near-neutral pH during early growth phases.
• Osmotic and ionic balance (literature):
  • Mineral salts (e.g., magnesium) serve as enzyme cofactors and help maintain membrane function and osmotic balance.
• Physical support (literature):
  • Agar provides a non-nutritive, inert gel matrix that enables discrete colony formation, spatial separation for selection, and reproducible diffusion profiles for indicators/antibiotics.
• Ecological/selective aspects (literature):
  • Carbohydrate sources and phosphate buffering can favor lactic streptococci over competing flora under appropriate incubation conditions (e.g., 30 °C, microaerophilic), enhancing recovery from dairy and fermentation-related samples.

Note: These roles are general to M17-type agar media. Specific quantitative composition and performance parameters for this product are Not specified for this item; refer to CoA/Spec Sheet.

Buffer Applications

This product is a complete culture medium rather than a simple buffering reagent. It is not typically used to formulate analytical buffers or titration systems.

• Context (literature):
  • M17 formulations include buffering capacity (often via phosphate/β-glycerophosphate) to maintain a near-neutral pH conducive to lactic streptococci growth, but the medium is not intended as a standalone buffer.
• Practical note:
  • If a defined buffer is required (e.g., phosphate, HEPES) for biochemical assays, prepare it separately and, if compatible with your organisms, use it to rinse or overlay cultures as per your SOP. Use M17 Agar primarily for plating and enumeration.

For precise pH targets and buffering components of this specific item, consult the product label and CoA/Spec Sheet.

Green Alternatives

While “green alternatives” usually refer to solvent or reagent substitutions, sustainability considerations for culture media focus on resource efficiency, renewable components, and waste minimization.

• Component sourcing (general/literature):
  • Agar is a renewable, seaweed-derived polysaccharide and a plant-based alternative to animal-derived gelling agents such as gelatin.
  • Complex nutrients (peptones/yeast extract) are byproducts of fermentation/hydrolysis; selecting suppliers with responsible sourcing can reduce environmental footprint.
• Process improvements:
  • Autoclaving optimization: Validate minimum effective sterilization cycles (e.g., fractional sterilization for some workflows) to reduce energy consumption while maintaining sterility assurance levels required by your SOPs.
  • Batch sizing: Prepare only the volume needed to reduce unused plate disposal.
  • Reusables: Employ reusable glassware and plate pourers; segregate uncontaminated packaging for recycling where available.
• Comparative view (literature):
  • M17 Agar vs alternatives for LAB
    • M17 Agar: Strong performance for lactic streptococci; neutral pH buffering; plant-derived gelling agent.
    • MRS Agar: Broader LAB coverage but may include additional components; selection should be driven by organism requirements and waste profile.

Tradeoffs: Shorter autoclave cycles or lower temperatures are not substitutes for validated sterilization. Always balance energy savings with biosafety and experimental integrity.

Pharmaceutical Uses

Direct pharmaceutical or excipient use is not applicable. M17 Agar is intended for research and laboratory microbiology only.

• Relevant laboratory/industrial contexts (literature):
  • Environmental monitoring, in-process control, and quality control of fermentation processes involving lactic acid bacteria (e.g., starter culture maintenance, contamination checks) in research and non-clinical manufacturing settings.
  • Strain banking and colony isolation for upstream process development.
• Regulatory note:
  • This product is not certified to pharmacopeial monographs and is not intended for clinical diagnostics or therapeutic manufacturing. Where culture media are used in GMP environments, users must qualify media lots and processes per internal validation protocols.

Always verify suitability with your QA/QC group and consult the CoA/Spec Sheet for lot-specific performance data.

Physical Properties

• Appearance: Not specified for this item; refer to CoA/Spec Sheet. (Typically a free-flowing, tan to beige dehydrated powder; literature)
• Physical state: Dehydrated blend; forms a firm gel upon dissolution in water, sterilization, and cooling (literature).
• Solubility: Freely soluble/suspendable in purified water with heating; insoluble in common organic solvents (literature).
• pH of prepared medium (literature): Typically near neutral; M17 media are commonly adjusted to pH ~6.8–7.1 at 25 °C prior to sterilization. Final pH may drift slightly after autoclaving and cooling depending on water and supplement profile.
• Gelation/melting (literature): Agar gels typically set at ~35–42 °C and melt at ~85–95 °C, enabling heat-sterilization followed by pour-plating when cooled to ~45–50 °C to protect heat-labile supplements and antibiotics.
• Density/bulk density: Not specified for this item; refer to CoA/Spec Sheet.
• Water content and ash: Not specified for this item; refer to CoA/Spec Sheet.
• UV/optical properties: Not specified for this item; refer to CoA/Spec Sheet. (Agar media generally exhibit light yellow to amber coloration when poured; literature.)

Important: Numerical property values above are general literature descriptions for M17-type agar and agar gels and are not item-specific specifications. For exact performance parameters (e.g., gel strength, final pH, preparation concentration), follow the product label and consult the lot CoA/Specification Sheet.

Quality & Grades

• Grade: BioReagent (item-specific)
  • Meaning: BioReagent grade indicates suitability for biological research applications, including preparation of culture media and routine microbiology workflows, with attention to contaminant levels (e.g., inhibitory metals, peroxides, and microbial bioburden) that could impact cell growth. It does not imply clinical/diagnostic suitability.
  • Implications: Lots are typically qualified by growth promotion testing (GPT) and/or performance characteristics relevant to the intended organisms (literature practice). Specific acceptance criteria for this item are Not specified for this item; refer to CoA/Spec Sheet.
• Stabilizers/antimicrobials: Not specified for this item; refer to CoA/Spec Sheet. (Media should be free of bacteriostatic agents that could suppress target organisms unless intentionally supplemented.)
• What to check on receipt:
  • Certificate of Analysis: Verify recommended preparation concentration (g/L), expected final pH, and growth promotion organisms/ATCC strains, if listed.
  • Physical integrity: Free-flowing powder without caking or foreign matter; uniform color.
  • Performance: If your application is regulated or critical, perform in-house GPT using your strains and water source.
• Comparability and validation:
  • When switching suppliers or lots, validate equivalence using side-by-side cultures for colony morphology, recovery rate, and selectivity (if applicable for supplements).
  • Record sterilization profiles and cooling/pour temperatures to maintain consistency.

Note: For lot-specific specifications (e.g., moisture content, gel strength, final pH), consult the product label and CoA/Spec Sheet.

Reaction & Applications

This product functions as a culture medium rather than a reagent for chemical transformations; classical organic reactions are not applicable. Practical applications center on microbial cultivation and analysis.

• Microbiological applications (literature):
  • Selective support for growth and enumeration of lactic streptococci and related lactic acid bacteria (LAB), including quality assessment of dairy fermentations and starter culture maintenance.
  • Colony isolation, morphology assessment, and strain purification on a firm agar surface.
  • Viable count determination (CFU) from environmental, food, or process samples where LAB recovery is desired.
• Functional features contributing to performance (literature):
  • Rich nitrogen sources (peptones/yeast extract) supply amino acids, peptides, vitamins, and growth factors.
  • Phosphate buffering (often via β-glycerophosphate in M17 formulations) helps stabilize pH near neutral despite lactic acid production.
  • Agar hydrogel provides a stable, inert matrix with minimal nutritive value, preventing colony spreading and enabling discrete colony formation.
• Practical tips:
  • Use fresh, high-purity water; confirm final pH and adjust before sterilization if your SOP requires.
  • For differential or selective applications, supplement with specific carbohydrates (e.g., lactose) or antibiotics as appropriate for the organism and study design; filter-sterilize supplements and add post-autoclave at ~45–50 °C.
  • Validate growth promotion with representative LAB strains after any process change (water source, autoclave cycle, supplement lot).

Note: All uses are for research/laboratory purposes only.

Reaction Conditions

In place of chemical reaction parameters, the relevant “conditions” are those for medium preparation, sterilization, and incubation (literature guidance):

• Reconstitution and sterilization:
  • Weigh the dehydrated medium per the product label (g/L). Disperse in purified water with stirring. Heat with gentle boiling until fully dissolved.
  • Adjust pH if required by your SOP (typically near neutral for M17-type media), then dispense into bottles or flasks.
  • Autoclave at 121 °C for 15 minutes (gravity or pre-vacuum cycle as validated). Do not over-sterilize to avoid caramelization and nutrient degradation.
• Plate pouring:
  • Cool to ~45–50 °C. If using heat-labile supplements (e.g., antibiotics, sugars, indicators), add aseptically at this stage. Mix gently to avoid bubbles and pour 20–25 mL per standard Petri plate.
  • Allow plates to solidify; dry surface in a laminar flow hood if excess condensation is present.
• Incubation (typical for lactic streptococci; literature):
  • Inoculate and incubate at ~30 °C for 24–48 h. Microaerophilic conditions may improve recovery for some LAB; anaerobic jars or reduced oxygen incubators can be used as needed.
• Expected outcomes:
  • Discrete, round colonies with morphology characteristic of the target LAB; perform growth promotion tests with reference strains when qualifying new lots.

All parameters above are general literature guidance. For item-specific instructions, follow the product label and CoA.

Safety & Handling

• Research use: For research use only. Not for human or animal diagnostic or therapeutic use.
• GHS information (item-specific):
  • Signal Word: Not specified for this item; refer to SDS.
  • Hazard Statements: Not specified for this item; refer to SDS.
  • GHS Classification and Pictograms: Not specified for this item; refer to SDS.
• General safety considerations (literature/best practice):
  • Low acute hazard expected for typical microbiological media; treat as laboratory chemical. Avoid inhalation of dust and contact with eyes/skin. Use appropriate PPE: lab coat, safety glasses, and gloves.
  • Handle sterile media to prevent contamination. Work near a flame or in a biosafety cabinet as appropriate for organism risk group.
  • Thermal hazards: Hot media (~100 °C post-sterilization) can cause burns. Allow to cool to ~45–50 °C before handling/pouring; use heat-resistant gloves.
  • Biological risk: Once inoculated, plates/broths contain live cultures. Follow institutional biosafety procedures (BSL-1/2 as applicable to the organism). Decontaminate by autoclaving before disposal.
  • Incompatibilities: Strong oxidizers and reactive chemicals are not typically used with media; store away from moisture and volatile contaminants that can alter performance.
• First aid (overview; defer to SDS):
  • Inhalation of dust: Move to fresh air; seek medical attention if irritation persists.
  • Skin/eye contact: Rinse with water for several minutes; remove contaminated clothing. Get medical advice if irritation continues.
  • Ingestion: Rinse mouth; seek medical advice if unwell.

Always consult the SDS for authoritative hazard, exposure limits, and spill/cleanup guidance.

Solvent Selection

This product is a dehydrated microbiological medium designed to be reconstituted in water; conventional solvent selection paradigms for organic synthesis do not apply.

• Primary solvent (applicable):
  • Highly purified water (e.g., ASTM Type I/II or equivalent microbiological-grade water) is recommended for consistent performance. Water quality (ionic content, TOC, microbial load) can influence gel strength and organism recovery (literature).
• Miscibility and preparation (literature):
  • The powder readily disperses in cold water with agitation; complete dissolution typically requires heating to near boiling prior to sterilization. Media are sterilized by autoclaving (e.g., 121 °C, 15 min) and poured while warm (45–50 °C).
• When to choose M17 Agar vs alternatives (literature):
  • M17 Agar is preferred for lactic streptococci and related LAB. For lactobacilli, MRS Agar is commonly used; for general heterotrophs, Plate Count Agar (PCA) or Tryptic Soy Agar (TSA) may be more appropriate.
• Additives and supplements:
  • Heat-labile antibiotics, indicators, or carbohydrate supplements should be sterile-filtered and added aseptically after autoclaving when the base medium cools to ~45–50 °C.

For precise reconstitution concentration and pH, follow the preparation instructions on the product label and verify with the lot CoA.

Storage & Reconstitution

• Storage conditions (item-specific): Room temperature. Protect from moisture and volatile contaminants. Keep container tightly closed when not in use.
• Shipping (item-specific): Shipped under normal conditions.
• Shelf life: Not specified for this item; refer to CoA/Spec Sheet. Use oldest stock first (FIFO) and minimize repeated exposure to humid air.
• Reconstitution (general, literature):
  • Reconstitute in purified water at the concentration stated on the product label (g/L). Heat to fully dissolve; adjust pH if required by your method. Sterilize by autoclaving (e.g., 121 °C, 15 min). Cool to 45–50 °C before adding heat-labile supplements and pouring plates.
• Prepared media storage (literature):
  • Plates: Store inverted in sealed sleeves or bags at 2–8 °C. Typical usability window is 2–4 weeks, depending on supplements and storage conditions. Monitor dryness and contamination.
  • Bottled media: Store at 2–8 °C; avoid repeated melting/solidifying cycles that can degrade agar and nutrients.
• Freeze–thaw: Not applicable to dehydrated powder. Avoid freezing hydrated media unless validated for your workflow; ice crystal formation can damage gel structure.
• Research use note: For research use only. Not for human or animal diagnostic or therapeutic procedures.

For lot-specific preparation instructions (concentration, expected pH, growth promotion criteria), consult the product label and CoA/Spec Sheet.

Structure & Identity

M17 Agar is a dehydrated, composite microbiological medium solidified with agar; it is a multicomponent preparation, not a single defined chemical entity.

• Item-specific identifiers
  • 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)
  • CAS: Not specified for this item; refer to CoA/Spec Sheet.
  • CID: Not applicable (mixture)
• Structural features (general/literature)
  • Contains a complex mix of organic nutrients (peptones, yeast extracts, phosphate salts), mineral ions (e.g., Mg2+), and the polysaccharide gelling agent agar (primarily agarose and agaropectin backbones built from repeating galactose units).
  • The 2D “structure” is best described functionally: a heterogeneous blend where low–molecular-weight nutrients, buffering salts, and vitamins are embedded in a solid hydrogel matrix upon cooling below the agar gelation temperature.
  • No stereochemical designation is applicable to the product as a whole; components may include diverse chiral amino acids and peptides derived from protein hydrolysates.
• Identity context (literature)
  • “M17” formulations were developed for cultivation and enumeration of lactic streptococci and related lactic acid bacteria. The “Agar” variant includes agar to yield a firm surface for colony isolation and enumeration.

Note: Because this is a complex mixture, definitive structural identifiers do not apply. For lot-specific composition ranges and performance criteria, consult the product label and Certificate of Analysis (CoA).

Synthetic Utility

Not applicable to chemical synthesis. M17 Agar is a microbiological medium and does not participate as a reagent or catalyst in synthetic organic/inorganic transformations.

• Related practical utility (literature):
  • As a solid growth matrix, M17 Agar enables discrete microbial colonies that can be screened for metabolic/synthetic phenotypes (e.g., lactic acid production, carbohydrate utilization) in microbial strain engineering workflows.
  • Agar plates support replica plating, selection, and library maintenance steps in strain construction—operations adjacent to, but distinct from, chemical synthesis.

For chemical reaction design, refer to dedicated reagents and solvents; use M17 Agar exclusively for microbial cultivation tasks.

Target Specificity

No antibody or molecular targeting information applies to this product, and no item-specific target data are provided.

• Context (literature): M17 Agar is broadly suitable for recovery of lactic streptococci and related lactic acid bacteria, but it is not selective for a single defined species without additional supplements/conditions.

For organism-specific selectivity and performance acceptance criteria, consult your internal methods and the item’s CoA/Spec Sheet.