Antibiotic Medium 2 (USP) - BioReagent

Cat. No.: A1528613

GRADE & PURITY BioReagent

Storage

Room temperature

Shipped In

Normal

Overview

For microbiological assay of antibiotic potency. Preparation method: Weigh 25.5 g of this product in 1 L of distilled or deionized water (the volume may be scaled up or down proportionally), 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 item-specific, manufacturer-verified protocols are provided in the Product Data. The following is general guidance for agar diffusion (cylinder-plate) antibiotic assays using Antibiotic Medium 2 (USP). Always follow your validated SOP and the current pharmacopeial chapter.

General agar diffusion assay workflow (informational):

• Medium preparation: Reconstitute the dehydrated medium in purified water. If agarized medium is required, add the specified agar amount per method. Autoclave, cool to the pouring temperature, and verify pH.
• Plate preparation: Pour plates to the validated depth and allow to solidify. Prepare a uniform lawn (seed layer) using the designated test organism at the required turbidity.
• Standards and samples: Prepare serial dilutions of the antibiotic reference standard and test samples in the prescribed diluent. Load cylinders or wells with equal volumes.
• Incubation: Incubate plates at the temperature and duration specified by the method. Avoid edge effects by equilibrating plates and controlling humidity.
• Reading and calculations: Measure zones of inhibition with a calibrated device. Construct a standard curve and interpolate sample potency. Include system suitability criteria (e.g., correlation coefficient, parallelism, zone range) per the method.

Note: Specific organisms, inoculum densities, plate depths, temperatures, and times are defined by the applicable USP monograph. Record all critical parameters for traceability.

Biological Roles

As a complex nutrient medium, Antibiotic Medium 2 (USP) provides the biochemical milieu necessary for robust, reproducible growth of designated microbial test strains in antibiotic potency assays.

• Carbon and energy sources: Complex carbohydrates and amino acid-derived carbon support central metabolism (glycolysis, TCA cycle) in the test organisms (general literature).
• Nitrogen sources: Peptones/enzymatic digests furnish amino acids and small peptides for protein synthesis and growth (general literature).
• Growth factors: Yeast/beef extracts contribute vitamins (e.g., B-complex) and trace elements that serve as enzyme cofactors, supporting consistent growth kinetics (general literature).
• Ionic balance and buffering: Inorganic salts help maintain osmotic balance and may contribute to the target pH after sterilization and cooling, enabling consistent antibiotic diffusion characteristics (general literature).
• Assay relevance: The medium’s formulation is tuned to yield confluent lawns and predictable antibiotic diffusion, critical for correlation of inhibition zones with antibiotic concentration using standard curves (general literature).

Note: The specific composition requirements and test organisms are dictated by pharmacopeial procedures. Users should adhere to the current USP monograph for Antibiotic Medium 2 and verify growth-promotion with the exact strains called for in their method. No therapeutic or clinical claims are made; this material is provided strictly for research and laboratory assay use.

Buffer Applications

Not primarily a buffer. Antibiotic Medium 2 (USP) is a complex growth medium used for microbiological assays of antibiotics. While the prepared medium will exhibit a defined pH suitable for the assay (per USP), it is not used as a dedicated buffering system.

Practical note (general):

• Verify pH after sterilization and cooling to the measurement temperature specified by the USP method. If your procedure includes pH adjustment, use sterile, compendial-grade acids/bases and document the adjustment as part of method control. Avoid over-adjustment that can alter organism growth or antibiotic stability.

Green Alternatives

This product is a nutrient medium rather than a solvent or reagent typically associated with green chemistry substitution. Nonetheless, sustainability can be addressed through practice and procurement:

• Waste minimization: Prepare only the volumes required for scheduled assays. Unused prepared medium should be minimized to reduce autoclave/biowaste loads.
• Energy efficiency: Batch autoclave cycles efficiently (full loads) and use validated shorter cycles where acceptable to reduce energy consumption.
• Water stewardship: Use appropriately graded purified water systems with efficient recirculation and recovery, and avoid repeated small-scale rinses during cleaning by adopting validated CIP/SIP procedures.
• Packaging choices: Select larger pack sizes when it aligns with usage rates to decrease packaging waste and shipment frequency. Recycle containers when decontaminated and permitted by local regulations.
• Alternative formats: In some workflows, ready-to-use sterile plates or media may reduce in-lab energy/water use; however, they may increase packaging and shipping footprint. Balance trade-offs based on your facility’s sustainability goals.

There are no “greener” chemical substitutes for Antibiotic Medium 2 (USP) itself because its composition and performance are tied to pharmacopeial criteria. Any change in medium type should be supported by revalidation against the governing method.

Pharmaceutical Uses

Role in pharmaceutical QC (no therapeutic claims):

• Antibiotic Medium 2 (USP) is used in laboratory settings that support pharmaceutical quality control to perform microbiological potency assays of antibiotic drug substances and products, following compendial methods. It facilitates standardized growth and diffusion characteristics required for system suitability and reportable results in agar diffusion/cylinder-plate assays.

Regulatory and method context (general):

• Assays are typically conducted under pharmacopeial guidance (e.g., USP chapters governing antibiotic bioassays). The medium choice is integral to method validity; substitutions require revalidation and documented equivalency.
• Reference standards: Use certified reference antibiotics for calibration curves as per the monograph. The medium’s performance should enable linear response over the specified concentration range for the target antibiotic.

Operational considerations:

• Lot qualification: Each lot should be qualified for growth promotion and zone-size conformity with designated organisms per internal SOPs.
• Stability studies and release testing: The medium supports potency determinations during stability programs and routine batch release where microbiological assay endpoints are specified by the method.

This product is intended for research and laboratory QC use only and is not a finished dosage form, excipient, or diagnostic product.

Physical Properties

Item-specific data

• Appearance: Not specified for this item; refer to CoA/Spec Sheet.
• Molecular Weight: Not applicable (mixture)

General/literature expectations for dehydrated microbiological media (informational only, not item specifications)

• Physical state: Typically a free-flowing, hygroscopic dehydrated powder designed for dissolution in purified water prior to sterilization (literature/general).
• Solubility: Formulated to be water-soluble or water-dispersible to prepare broth or agar-containing media as per USP procedures (literature/general).
• pH of prepared medium: Defined by the relevant USP monograph for Antibiotic Medium 2 at a specified temperature; users should verify pH after sterilization and cooling (literature/general). Specific numeric pH range is not provided here.
• Density, melting/boiling point, refractive index, logP, pKa: Not applicable or not meaningful for this heterogeneous mixture in dehydrated form.

Notes

• For any lot-specific physical characteristics (e.g., color tone, clarity of prepared medium, pH), consult the lot CoA and follow USP acceptance testing. Do not treat common literature values as specifications; verify performance with the required test strains and assay format.

Quality & Grades

Item-specific grade information

• Grade: BioReagent. This denotes suitability for biological research workflows and routine microbiology where reliable growth performance and low bioburden are required. It is not a clinical/diagnostic product and is for research use only.

What BioReagent means in practice

• Raw material control: Components are selected and blended to meet defined performance criteria (growth promotion, clarity, pH post-sterilization) rather than a single-chemical purity metric.
• Performance orientation: For USP Antibiotic Medium 2, the critical quality attribute is fitness-for-use in pharmacopeial antibiotic microbiological assays (e.g., reproducible growth and diffusion characteristics for specified organisms). Users should qualify each lot using their compendial method.
• Documentation: Lot-specific Certificate of Analysis (CoA) typically includes appearance, pH of prepared medium, and growth-promotion/performance results with specified strains. Always verify against your internal method and the current USP chapter governing antibiotic assays.

Stabilizers/antifoams

• Any stabilizers or anti-caking agents, if present, would be disclosed on the CoA/specification. Not specified for this item; refer to CoA/Spec Sheet.

Comparison to other grades (general guidance)

• Microbiological/USP assay media focus on performance with test strains. In contrast, cell culture or molecular biology grades may emphasize endotoxin, DNase/RNase, or mycoplasma limits. Select the medium based on the regulatory context and assay acceptance criteria you must meet.

Reaction & Applications

Primary application (USP microbiological assay of antibiotics)

• Antibiotic Medium 2 (USP) is designed for compendial microbiological assays (e.g., cylinder-plate or agar diffusion tests) to quantify antibiotic potency by measuring zones of inhibition around antibiotic-containing reservoirs against specified test organisms. It supports consistent growth and diffusion characteristics required for accurate standard curves and sample comparison.

Use contexts (general, not exhaustive)

• Quality control of antibiotic drug substance and drug products in accordance with pharmacopeial chapters governing antibiotic bioassays.
• Method development/verification for microbiological assay conditions (e.g., seed layer density, plate thickness, incubation parameters) when establishing validated potency assays.
• Routine laboratory potency checks for stability studies, manufacturing in-process controls, and release testing where a microbiological endpoint is required by method or regulation.

Practical notes (general guidance)

• Medium preparation: Dissolve the dehydrated medium in purified water with gentle heating; adjust volume; sterilize per validated method. Verify pH at the test temperature specified by the USP monograph after sterilization and cooling.
• Performance verification: Conduct growth-promotion tests with prescribed strains and verify acceptable zone diameter ranges using the reference antibiotic standards. Record plate depth and inoculum uniformity, as these affect diffusion.
• Controls: Include system suitability with a defined standard curve and replicate plates. Ensure antibiotic stock solutions are prepared with certified reference standards and appropriate diluents.

No medical/clinical diagnostic claims are made. For research and laboratory QC use consistent with compendial methods.

Reaction Conditions

Chemical reaction conditions are not applicable to this product. However, for the intended microbiological assay workflows, the following general laboratory conditions apply (informational, not item specifications):

• Preparation: Dissolve the dehydrated medium in purified water with gentle heat and stirring until fully dissolved. For agar media, incorporate agar prior to sterilization, ensuring complete hydration.
• Sterilization: Autoclave according to validated parameters. Use containers rated for pressure; avoid tight sealing. Allow medium to cool to the specified pouring temperature before plating.
• pH: Verify pH after sterilization and cooling. Adjust only if permitted by the compendial method using sterile acid/base.
• Incubation: Inoculated assay plates are incubated at the temperature and duration specified by the relevant USP method for the test organism and antibiotic. Maintain tight control of plate depth and incubation humidity to ensure reproducible diffusion and zone measurement.

Consult the current USP chapter and your internal SOPs for exact conditions, organisms, and acceptance criteria. Do not treat this guidance as a specification.

Safety & Handling

GHS classification and hazard statements

• Signal word: Not specified for this item; refer to SDS.
• H-statements: Not specified for this item; refer to SDS.
• GHS classification/pictograms: Not specified for this item; refer to SDS.

General laboratory safety guidance (informational, defer to SDS/USP)

• Handle as a laboratory chemical/biological nutrient mixture. Avoid inhalation of dust and contact with eyes/skin. Use in a fume hood or well-ventilated area to minimize airborne dust.
• Recommended PPE: Lab coat, safety glasses or face shield, and appropriate disposable gloves. Use respiratory protection if dust generation cannot be controlled (per institutional risk assessment).
• Incompatibilities: Store away from strong oxidizers and moisture. Hygroscopic components can cake; keep container tightly closed with desiccant as needed.
• First aid (overview; consult SDS): Inhalation—move to fresh air; Eye contact—rinse cautiously with water for several minutes; Skin—wash with soap and water; Ingestion—rinse mouth and seek medical advice if unwell.
• Microbiological practices: Although the powder is non-sterile nutrient media, once reconstituted and inoculated it constitutes biohazardous material. Follow BSL-appropriate practices and autoclave all waste and unused prepared medium before disposal.
• Thermal processing: Autoclave only in vessels rated for pressure; do not tightly seal during sterilization. Exercise caution when handling hot media to prevent burns.

Always consult the SDS and institutional EHS policies for authoritative safety and disposal guidance.

Solvent Selection

Not a solvent. Antibiotic Medium 2 (USP) is a dehydrated culture medium intended to be reconstituted in purified water.

Useful guidance (general):

• Reconstitution solvent: Use freshly prepared purified water (e.g., ASTM Type 1/Type 2 or equivalent) per your validated method. Avoid hard/ion-rich water that can affect medium clarity, pH, or antibiotic diffusion.
• Optional agar addition: If an agarized assay medium is required, add the specified agar amount (per USP method) before sterilization. Allow complete hydration and boiling prior to autoclaving.
• Filtration vs autoclaving: Autoclaving is commonly used for sterilization of this type of medium. If filter-sterilizing, confirm complete dissolution and use membranes compatible with the medium (typically 0.22 µm PES or cellulose acetate). Follow your validated compendial procedure.

Storage & Reconstitution

Item-specific storage and shipping

• Storage conditions: Room temperature (from Product Data). Protect from moisture. Keep tightly closed.
• Shipped in: Normal conditions (from Product Data).

Reconstitution and use (general guidance; not item specifications)

• Water quality: Use purified water meeting your laboratory’s validated specifications (e.g., ASTM Type 1/2 or compendial water) to reconstitute the medium.
• Dissolution: Add the dehydrated medium to water with stirring and gentle heat until fully dissolved. For agar media, ensure complete agar hydration (bring to a brief boil if required by SOP) before sterilization.
• Sterilization: Autoclave according to your validated cycle. Do not tightly cap containers. Allow to cool to the specified pouring temperature before dispensing plates.
• pH check: Verify and, if permitted by the method, adjust the pH after sterilization and equilibration to the measurement temperature.
• Shelf life of prepared medium: Not specified for this item; refer to CoA/Spec Sheet. As general practice, store prepared sterile medium at 2–8°C protected from light, and use within the timeframe validated by your laboratory to maintain performance.
• Freeze–thaw: Not applicable. Do not freeze prepared agar plates unless your validated method permits and supports performance.

Always consult the lot-specific CoA and the current USP monograph for Antibiotic Medium 2 for exact preparation instructions and acceptance criteria.

Structure & Identity

Overview

• This product is a complex, undefined microbiological growth medium standardized as Antibiotic Medium 2 (USP). It is a dehydrated blend of nutrient components intended for reconstitution in purified water for microbiological assays of antibiotics.
• Because it is a formulated mixture, it does not have a single molecular structure, SMILES, InChIKey, molecular formula, or molecular weight.

Item-specific identifiers (from Product Data)

• Product name: Antibiotic Medium 2 (USP)
• Grade: BioReagent
• Storage: Room temperature; shipped under normal conditions
• Research use: For research use only

Structural features (general knowledge for complex media; not compound-specific)

• Typical constituents of USP antibiotic assay media include peptones/enzymatic digests (amino acids/peptides), yeast/beef extracts (vitamins, growth factors), mineral salts, and sometimes defined carbohydrates. Exact component grades/levels are controlled by pharmacopeial performance criteria rather than a single chemical structure.

2D description in words (general for the class)

• Heterogeneous mixture of low- to mid-molecular-weight organics (amino acids, peptides, vitamins), inorganic ions, and any USP-specified additives that collectively provide a balanced nutritional environment to support growth of designated test organisms for antibiotic bioassays.

Unavailable identifiers for this item

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

Synthetic Utility

Not applicable. Antibiotic Medium 2 (USP) is a complex biological growth medium and is not used as a reagent or building block in synthetic organic or inorganic chemistry. For chemical synthesis guidance, refer instead to the specific reagents and solvents relevant to your transformation.

Target Specificity

Not applicable. This product is a culture medium, not a biological targeting reagent (e.g., antibody, ligand, enzyme inhibitor). It does not possess molecular target specificity. Any organism specificity arises from the assay design and selected test strains defined by the compendial method.