Antibiotic Medium 1 (USP) - BioReagent

Cat. No.: A1528569

GRADE & PURITY BioReagent

Storage

Room temperature

Shipped In

Normal

Overview

For microbiological assay of antibiotic potency. Preparation method: Weigh 30.5 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. After sterilization, shake well to prevent agar from settling and solidifying at the bottom of the vessel, then set aside for use.

Specifications

Specifications & Purity

BioReagent

Storage

Room temperature

Shipped In

Normal

Grade

BioReagent

Product Line

biological_products

Application Protocols

• No manufacturer-validated protocols are provided in the Product Data. The following outlines general, literature-based workflows for antibiotic potency assays using media of this class. Adjust to your validated method and consult the CoA.
• Cylinder-plate (agar diffusion) assay (literature/general):
  1. Prepare medium at recommended concentration; autoclave and cool to ~45–50 C. Pour base layer into sterile plates to a uniform depth (e.g., ~4 mm). Allow to solidify.
  2. Prepare a seed layer by mixing inoculum (standardized density) with molten medium at ~45–50 C and overlay onto base.
  3. Place cylinders or cut wells; add reference standard solutions and test samples in replicate across the assay range.
  4. Incubate at the specified temperature until zones are well-defined. Measure diameters and compute potencies via standard curve/parallel-line analysis.
• Turbidimetric assay (literature/general):
  1. Prepare sterile broth form of the medium.
  2. Inoculate standardized cells into tubes/microplates containing graded concentrations of reference and test articles.
  3. Incubate and record turbidity (e.g., OD at 530–650 nm) at fixed times. Construct calibration and calculate sample potency.
• Controls and suitability:
  • Include sterility controls, growth-promotion controls, and system suitability checks per the pharmacopeial chapter.
• Item-specific instructions: Not specified for this item; refer to CoA/Spec Sheet.

Biological Roles

• Nature of product: The medium itself has no intrinsic biological function in vivo; it provides an ex vivo nutrient environment for microbes.
• Role in microbiology (literature/general):
  • Supplies amino acids, peptides, vitamins, and minerals to support growth of designated indicator organisms used in antibiotic potency assays. The matrix consistency and nutrient level are chosen to produce reproducible growth rates and antibiotic sensitivity profiles.
  • For diffusion assays, the agar (if present) forms a semi-solid matrix through which antibiotics can diffuse, enabling measurement of inhibition zones proportional to potency within a defined range.
  • For turbidimetric assays, the broth version supports uniform growth, allowing spectrophotometric monitoring of turbidity changes in response to antibiotic concentrations.
• Factors affecting biological performance:
  • pH and ionic composition influence antibiotic activity (e.g., aminoglycosides and tetracyclines are pH-sensitive).
  • Divalent cations (Mg2+, Ca2+) can modulate susceptibility to certain antibiotics; water quality and supplements must be controlled.
  • Inoculum density, incubation temperature, and time strongly impact endpoint readings; these should be standardized per compendial methods.
• Quality controls:
  • Growth promotion with control strains, sterility checks of prepared media, and parallel testing with reference standards ensure the medium supports the intended biological response.

Buffer Applications

• Applicability: This product is a complex nutrient medium and is not designed as a defined buffering system.
• Context (literature/general):
  • Many microbiological media exhibit inherent buffering capacity from phosphates, amino acids, and peptides, yielding a near-neutral working pH suited to common assay organisms. However, the exact buffer species and capacity depend on the specific formulation and are supplier-dependent.
• Practical guidance:
  • If a pharmacopeial assay specifies a target pH, verify and, if necessary, adjust the medium prior to sterilization using dilute acid/base, recognizing that autoclaving can shift pH slightly.
  • For methods requiring tighter pH control or alternative pH ranges, prepare a separate sterile buffer (e.g., phosphate, MOPS, HEPES; selection depends on organism and antibiotic stability) and combine aseptically per the validated procedure.
• Non-applicability:
  • Not typically used as a running buffer for electrophoresis or for cell-free biochemical assays that demand precise ionic compositions. Choose dedicated buffer systems for those applications.
• Item-specific buffer specifications (pH range, buffer components): Not specified for this item; refer to CoA/Spec Sheet.

Green Alternatives

• Goal: Reduce environmental footprint and improve safety while maintaining assay fidelity.
• Considerations for this medium type (literature/general):
  • Energy reduction: Optimize autoclave loads and cycles; prepare only the volume required to minimize re-melting/sterilization. Use validated shorter cycles where allowed by SOPs and compendia.
  • Waste minimization: Prepare small batches; plate only what is needed. Decontaminate spent media via autoclaving and segregate plastics for appropriate disposal or recycling where permitted.
  • Water stewardship: Use accurately measured high-purity water; avoid unnecessary rinses by adopting clean-in-place practices for glassware.
  • Safer supplements: When optional indicators or antibiotics are added, choose less hazardous solvents for stock solutions (e.g., water or low-toxicity alcohols) and filter-sterilize instead of heat sterilizing heat-labile additives.
• Comparison (informational; not item-specific):
  • Dehydrated media (this item type):
    • Pros: Long shelf life at room temperature; reduced cold-chain; lower transport mass/volume.
    • Cons: Requires sterilization energy and single-use plastics for plate pouring.
  • Ready-to-use plates/broths:
    • Pros: Lower in-lab energy use; reduced operator exposure to hot liquids.
    • Cons: Higher packaging waste; greater cold-chain footprint and potential for expired inventory.
• Implementation tips:
  • Standardize batch sizes, adopt reusable glass Petri dishes where feasible, and schedule combined autoclave runs to improve energy efficiency without compromising sterility.

Pharmaceutical Uses

• Scope: Research and quality-control contexts only; no clinical or therapeutic claims.
• Application in pharmaceutical QC (literature/general):
  • Commonly employed as the base medium for compendial microbiological assays of antibiotic potency (e.g., cylinder-plate/diffusion and turbidimetric assays described in USP/Ph.Eur.). The medium supports standardized growth of indicator organisms to quantify active content in antibiotic drug substances and products by comparison to reference standards.
  • Utilized in method validation/verification, growth-promotion testing, and routine release/stability testing of antibiotic batches.
• GMP considerations:
  • In regulated environments, each lot should be qualified per SOPs: verify growth-promotion suitability, sterility after preparation, and conformity to pH/gel-strength (if agar) as applicable. Maintain traceability of lots, preparation records, and environmental conditions for plate pouring and incubation.
  • For potency assays, document calibration curves, system suitability criteria (e.g., parallelism, linearity), and acceptance limits for zone diameters or turbidity responses.
• Item-specific pharmacopeial compliance statement: Not specified for this item; refer to CoA/Spec Sheet for any compendial claims and performance data.

Physical Properties

• Item-specific physical constants (specifications):
  • Appearance: Not specified for this item; refer to CoA/Spec Sheet.
  • Molecular Formula / Molecular Weight: Not applicable to mixtures; not specified for this item.
  • Density, pH (as prepared), moisture content, ash, gel strength: Not specified for this item; refer to CoA/Spec Sheet.
• Storage and shipping (from Product Data):
  • Storage Conditions: Room temperature
  • Shipped In: Normal
• General/literature characteristics for dehydrated microbiological media (informational, not specs):
  • Form: Free-flowing, hygroscopic, tan-to-beige powder; becomes a clear to slightly opalescent solution upon heating in water; if agar-containing, forms a firm gel on cooling after sterilization.
  • Solubility: Dispersible in water; complete dissolution typically requires heating to near boiling prior to sterilization. Insoluble in organic solvents.
  • Typical working concentration: Manufacturer-specific; often 20–40 g/L depending on formulation and whether agar is included. Consult item CoA for exact mass-per-liter.
  • Typical pH (after sterilization at working concentration): Commonly near neutral (≈6.5–7.2), but target pH is media- and supplier-dependent.
  • Stability: Stable as a dry blend when protected from moisture, heat, and light; solutions/plates are perishable and should be used promptly or stored refrigerated per lab practice.
• Important note: Because this is a complex blend, precise physicochemical constants (bp, mp, logP, refractive index) are not defined.

Quality & Grades

• Item-specific grade (from Product Data):
  • Grade/Purity: BioReagent
• Interpretation of grade (general):
  • BioReagent indicates suitability for research and laboratory biological applications, with controls on bioburden/endotoxin and performance characteristics appropriate for microbiology or cell-related work. It does not imply clinical/diagnostic use.
• USP designation context (naming only):
  • The name “Antibiotic Medium 1 (USP)” reflects alignment with compendial media naming used in antibiotic potency assays. It does not by itself certify pharmacopoeial compliance for a specific lot; consult the Certificate of Analysis/Specification Sheet for confirmation of compendial conformity and performance metrics (e.g., growth promotion, pH range, inhibition zone performance).
• Stabilizers, additives, UV cutoff, metal limits, peroxide levels: Not specified for this item; refer to CoA/Spec Sheet.
• What to check on receipt:
  • Lot-specific composition statement and recommended mass-per-liter.
  • Growth-promotion/assay suitability test results against compendial organisms (where applicable).
  • Moisture content and appearance conformity.
• Practical implication:
  • For regulated QC environments, verify that the lot meets internal SOP acceptance criteria and any USP/Ph.Eur. method requirements before release to testing.

Reaction & Applications

• This section focuses on laboratory applications rather than chemical reactions because the product is a culture medium.
• Core application (literature/general):
  • Standardized base medium for microbiological assays of antibiotic potency, such as cylinder-plate (agar diffusion) and turbidimetric methods described in pharmacopeias (USP/Ph.Eur.). It supports growth of assay indicator strains and provides a reproducible matrix for diffusion or turbidity measurements.
• Typical use cases:
  • Preparation of seed/inoculum layers for plate assays to determine activity of antibiotics by zone-of-inhibition.
  • Preparation of base agar or broth for turbidimetric quantification using standard curves of reference antibiotic solutions.
  • Growth-promotion testing to verify medium suitability prior to potency assays.
• Practical tips:
  • Accurately weigh the dehydrated medium; use validated water and calibrated glassware to control concentration.
  • Adjust pH prior to sterilization only if required by the method; verify pH after autoclaving at use temperature.
  • For diffusion assays, ensure uniform agar depth (commonly ~4 mm) and consistent well/cylinder dimensions to limit variability.
  • Standardize inoculum density (e.g., 0.5 McFarland or method-specific OD) and incubate under controlled temperature/humidity to minimize edge effects.
• Documentation:
  • Maintain traceability to reference standards, strains, and method versions. Record lot numbers, preparation dates, and growth-promotion results to support QC and data integrity.

Reaction Conditions

• Chemical reaction conditions are not applicable. Instead, the following summarizes typical preparation conditions for media of this class (literature/general; verify against your method and CoA):
• Typical preparation parameters:
  • Concentration: Follow supplier’s recommended g/L. If unspecified, consult compendial method for the assay being performed.
  • Dissolution: Add dehydrated medium to high-purity water with vigorous stirring; heat to near boiling to ensure complete dissolution.
  • pH: Measure and, if needed, adjust to the method’s target value at room temperature before sterilization. Expect minor pH drift post-autoclave.
  • Sterilization: Autoclave at 121 C for 15–20 min (15 psi) for standard volumes; adjust time for larger volumes per validated load patterns. Do not overprocess.
  • Agar handling (if agar-containing): Cool to ~45–50 C before pouring plates or adding heat-labile supplements to avoid precipitation or degradation.
  • Incubation for growth-promotion: Inoculate control strains at prescribed density; incubate under method-specified conditions (often 30–37 C) and verify expected growth within the time window.
• Performance notes:
  • Ensure uniform plate depth and temperature equilibration to reduce edge effects in diffusion assays.
  • Use freshly prepared medium where method precision is critical; aging can alter water activity and diffusion properties.
• Item-specific times/temperatures/compositions: Not specified for this item; refer to CoA/Spec Sheet and your validated SOP.

Safety & Handling

• GHS information (from Product Data):
  • Signal Word, H-Statements, GHS Classification, Pictograms: Not specified for this item; refer to SDS for authoritative hazard information.
• General safety guidance for dehydrated culture media (literature/general):
  • Hazards: Low intrinsic toxicity is typical; main risks are dust inhalation, eye irritation, and slip hazards if spilled. After hydration and inoculation, treat as biohazard due to live microorganisms; follow institutional biosafety procedures.
  • PPE: Lab coat, safety glasses, and nitrile gloves. Dust mask/respirator as appropriate to limit inhalation of fine particulates during weighing/dispersion.
  • Handling: Avoid creating dust; use in a well-ventilated area or fume hood during weighing. Do not ingest. Avoid contact with eyes/skin.
  • Incompatibilities: Avoid moisture uptake; keep container tightly closed with desiccant as needed. No specific chemical incompatibilities in the dry state under normal lab conditions; avoid strong oxidizers in solution without risk assessment.
  • Thermal processing: During autoclaving, do not overfill vessels; loosen caps to prevent pressure buildup and bumping. Allow media to cool to ≈45–50 C before supplement addition (if applicable) and pouring plates.
  • First aid (overview; defer to SDS): Rinse eyes/skin with water for several minutes in case of contact; remove to fresh air if inhaled; seek medical attention if irritation persists.
  • Waste: Uninoculated waste can follow nonhazardous disposal per local rules. Inoculated media and plates must be autoclaved or otherwise decontaminated prior to disposal.

Solvent Selection

• Applicability: As a dehydrated microbiological medium, this product is intended to be reconstituted with water; organic solvent selection is not applicable.
• Water selection (literature/general guidance):
  • Use high-purity water (e.g., ASTM Type 1 or 2, or USP Purified Water) to minimize inhibitory ions and microbial contaminants.
  • Consider preheating water (≈60–80 C) to facilitate dissolution; bring to near boiling with stirring for complete solubilization before sterilization.
• Ionic strength and pH:
  • Media performance depends on final pH and ionic content. Avoid water sources with residual chlorine or high hardness that can alter assay outcomes.
• Comparison (informational):
  • Sterile ready-to-use media: saves time and reduces variability but has shorter shelf life and higher cost.
  • Dehydrated media (this item type): maximizes flexibility and shelf stability; requires autoclaving and aseptic technique.
• Additives:
  • If assay requires supplements (e.g., specific carbohydrates, buffers, divalent cation adjustments), sterilize separately by filtration when heat labile and add aseptically to cooled (≈45–50 C) sterile medium.
• Not recommended:
  • Do not attempt dissolution in alcohols or other organics; complex nutrients are not soluble and may denature.

Storage & Reconstitution

• Item-specific storage and shipping (from Product Data):
  • Storage Conditions: Room temperature
  • Shipped In: Normal
• Container handling:
  • Keep tightly closed to prevent moisture uptake. Store in a cool, dry place away from direct sunlight. Use desiccant where appropriate.
• Shelf life and stability:
  • Lot-specific expiry, recommended retest period, and moisture specifications: Not specified for this item; refer to CoA/Spec Sheet.
• Reconstitution/preparation (literature/general guidance; not item-specific):
  • Accurately weigh the recommended grams per liter of dehydrated medium (per CoA).
  • Suspend in high-purity water with stirring; heat to near boiling until fully dissolved.
  • Verify pH at room temperature and adjust only if required by your method.
  • Sterilize by autoclaving at 121 C for 15–20 minutes unless otherwise specified. Allow to cool to ~45–50 C before adding heat-labile supplements or pouring plates.
  • Store prepared plates at 2–8 C in sealed bags/containers to limit desiccation; bring to room temperature and dry surface condensation before use.
• Freeze–thaw guidance:
  • Not applicable to dry medium. Avoid freezing hydrated medium unless your method validates frozen storage; repeated freeze–thaw cycles of prepared media are not recommended.
• Research Use Note (from Product Data): For research use only.

Structure & Identity

• Item-specific identifiers (from Product Data):
  • SKU: A1528569
  • Product Name: Antibiotic Medium 1 (USP)
  • Grade/Purity: BioReagent
  • CAS, CID, InChIKey, SMILES: Not specified for this item; refer to CoA/Spec Sheet.
• Nature of material: This product is a complex, dehydrated microbiological culture medium (mixture), not a single defined chemical entity. As such, discrete molecular formula and molecular weight are not applicable.
• Structural features:
  • As a culture medium, it typically comprises a blend of peptones/tryptones, meat/yeast extracts, salts, and agar (if an agar form), providing amino acids, peptides, vitamins, minerals, and carbohydrates to support microbial growth and standardized antibiotic assays. (literature/general)
• 2D structural description: Not applicable to mixtures. Components, when present, are small molecules and biopolymers without a single unified structure.
• Synonym context (literature/general): “Antibiotic Medium No. 1 (USP)” is commonly referenced in compendial microbiological assay methods (e.g., cylinder-plate/diffusion or turbidimetric assays) as a standardized nutrient base for inoculum/seed layers. Exact composition varies by supplier; consult the CoA for this item’s detailed formulation.

Synthetic Utility

• Not a chemical reagent for synthesis. This product is a biological culture medium and does not serve as a building block, catalyst, or solvent in organic or inorganic synthesis.
• If used in method development (literature/general):
  • The only “preparative” operations involve dissolution in water, pH adjustment, sterilization (autoclaving), and optional supplementation. No synthetic transformations are associated with its use.
• For laboratories seeking synthetic analogs:
  • Select defined buffers, salts, or nutrient components individually (e.g., specific amino acids, yeast extract, peptone, agar) to construct custom media compositions when mechanistic studies require precise control of variables. This is outside the scope of this product’s intended use.

Target Specificity

• Not applicable. This product is a microbiological culture medium, not a biomolecular probe, antibody, or affinity reagent. There is no antigen/epitope, clone, isotype, or species reactivity associated with this item.
• Any organism performance characteristics (growth promotion, indicator strains) are method-dependent and lot-specific. Item-specific organism panels and results are Not specified for this item; refer to CoA/Spec Sheet.