Bismuth Sulfite Agar Medium (USP) - BioReagent

Cat. No.: B1528474

GRADE & PURITY BioReagent

Storage

Room temperature

Shipped In

Normal

Descripción general

For selective isolation of Salmonella. Preparation method: Weigh 5.23 g in 100 mL of distilled or deionized water, stir and boil to dissolve for 1 minute, adjust volume, cool to 50–55°C and pour into plates. It is recommended to prepare no more than 200 mL at a time; use after overnight storage and consume within 3 days.

Specifications

Especificaciones y pureza

BioReagent

Condiciones de almacenamiento de almacenamiento

Room temperature

Enviado en

Normal

Grado

BioReagent

Product Line

Productos biológicos

Application Protocols

The following is general, literature-based guidance for preparing and using Bismuth Sulfite Agar plates. For item-specific instructions (e.g., grams per liter, target pH), Not specified for this item; refer to CoA/Spec Sheet.

• Plate preparation (literature/general)

  1. Add the dehydrated medium to purified water in a heat-resistant vessel with stirring.
  2. Heat to near boiling until fully dissolved; avoid prolonged boiling.
  3. Do not autoclave unless explicitly directed by the manufacturer (selectivity may be lost).
  4. Cool to ~45–50 °C, mix gently to minimize bubbles, and pour into sterile Petri dishes.
  5. Allow plates to solidify; dry surface moisture in a laminar-flow hood. Store protected from light.

• Inoculation and incubation (literature/general)

  • Streak for isolation using a sterile loop from enrichment broth or sample suspension.
  • Incubate aerobically at 35–37 °C for 24–48 h. Examine for characteristic colony morphology (e.g., blackening from H2S reaction with ferrous ions).

• Quality control (literature/general)

  • Include a positive control strain (e.g., Salmonella enterica) and an inhibitory control (e.g., a Gram-positive organism) to verify performance per lab SOPs.

• Biosafety and disposal

  • Handle inoculated plates as biohazardous. Autoclave before disposal in accordance with institutional regulations.

Biological Roles

This product is not a biological macromolecule but a formulated growth medium that supports and selects for certain bacteria in research contexts.

• Functional role in microbiology (literature/general)

  • Nutritional components (peptones, beef extract, glucose) supply amino acids, peptides, vitamins, and energy sources for heterotrophic bacterial growth.
  • Selective agents (bismuth salts, brilliant green) suppress many Gram-positive organisms and competing Gram-negatives, enriching for Salmonella spp. and some related enterics.
  • Differential system: Sulfur metabolism is probed via H2S production; ferrous ions act as an indicator by forming black ferrous sulfide precipitates in colonies and surrounding agar.

• Workflow integration

  • Often used downstream of non-selective or mildly selective enrichment broths to facilitate recovery from low-inoculum or stressed cells.
  • Colonies exhibiting characteristic morphology (e.g., dark/black centers and surrounding zones due to H2S) are picked for further biochemical and/or molecular confirmation.

• Limitations and biological variability

  • Expression of H2S and tolerance to inhibitors are strain- and condition-dependent. Environmental stress, sample matrix, and incubation conditions can influence colony morphology and recovery.

No therapeutic or clinical claims are implied; the medium is for research use only, as stated in the Product Data.

Buffer Applications

This product is not a conventional buffer system; it is a complete culture medium. Therefore, typical buffer recipes and pH-range applications do not apply directly.

• Literature/general notes
  • Many Bismuth Sulfite Agar formulations include phosphate salts that provide buffering capacity near neutral pH to stabilize the medium during incubation.
  • If pH adjustment is required during preparation, it should be guided by the product’s instructions and conducted before gelation. Over-adjustment can impair selectivity and differential performance.

For buffer preparation needs (e.g., biological assays or chromatography), select a dedicated buffering system (phosphate, Tris, HEPES, etc.) rather than culture media.

Green Alternatives

• Environmental considerations (literature/general)

  • The medium contains bismuth salts (heavy metal) and the triphenylmethane dye brilliant green. These components can complicate waste handling. Minimize waste volumes and segregate unused medium/dye-containing waste per local regulations.

• Potential alternatives and trade-offs (general)

  • XLD Agar (xylose lysine deoxycholate): avoids heavy bismuth salts but still uses bile salts and phenol red dye; good differentiation via H2S on thiosulfate/iron. Selectivity differs; may admit more competing flora.
  • Hektoen Enteric Agar: uses bile salts and indicators (bromothymol blue, acid fuchsin) with thiosulfate/iron; no bismuth salts. Often less inhibitory to certain Salmonella strains but may permit more coliform background.
  • SS Agar (Salmonella–Shigella): no bismuth, but relatively harsh; can suppress some Salmonella strains; uses brilliant green in some variants.

• Process improvements

  • Use right-first-time preparation to avoid discarding degraded batches (energy and material savings).
  • Prepare plates in batches sized to near-term needs to reduce expired plate disposal.
  • Consider reusable glassware for pouring to reduce single-use plastics.

• Summary

  • There is no one-to-one “green” replacement that preserves all performance characteristics of Bismuth Sulfite Agar. Media such as XLD or Hektoen reduce heavy-metal burden but alter selectivity/differential outcomes. Selection should be guided by the sample matrix and method requirements.

Pharmaceutical Uses

• Scope

  • No therapeutic or clinical use is claimed. Per Product Data, this item is for research use only.

• Relevance to pharmaceutical quality control (literature/general)

  • Bismuth Sulfite Agar Medium (USP) is referenced in compendial microbiology as a selective/differential agar for the recovery of Salmonella spp. In pharmaceutical and related industries, comparable media are used in environmental monitoring, raw material testing, and investigational studies to support microbiological quality systems in accordance with pharmacopeial methods and internal SOPs.

• Practical considerations

  • For regulated applications, each lot should be qualified with growth-promotion testing using defined challenge strains and conditions per USP/Ph. Eur./JP or internal validation protocols.
  • Water quality, preparation method (especially heat exposure), and plate storage conditions are critical to reproducibility and should be documented in batch records.

• Documentation

  • For certificate needs (CoA, SDS, microbiological performance data), contact Aladdin Scientific. Item-specific compendial conformance claims, if any, are lot-dependent and Not specified for this item; refer to CoA/Spec Sheet.

Physical Properties

• Item-specific properties

  • Appearance: Not specified for this item; refer to CoA/Spec Sheet.
  • Molecular formula / molecular weight: Not applicable (multi-component medium). Not specified for this item; refer to CoA/Spec Sheet.
  • Other numeric specifications (water content, ash, particle size, pH of prepared medium): Not specified for this item; refer to CoA/Spec Sheet.

• Typical properties (literature/general for dehydrated Bismuth Sulfite Agar media)

  • Physical form: Dehydrated, free-flowing powder, generally light tan to greenish-beige depending on dye content and supplier.
  • Solubility: Designed to disperse in purified water; complete dissolution typically requires heating to near boiling.
  • pH of prepared medium (at 25 °C): commonly near neutral to slightly alkaline; typical literature values are around pH 7.6–7.8 (exact target per USP/brand may differ).
  • Optical: Prepared plates appear pale to olive green; blackening occurs locally during incubation where H2S-reactive colonies grow.
  • Stability: Stable as dry powder when stored tightly closed at room temperature in a dry, dark place. Prepared plates are light- and time-sensitive due to selective agents and dye.

• Notes

  • Do not autoclave many BS agar formulations because heat-sensitive selective components (e.g., bismuth sulfite/brilliant green) can degrade; follow the item’s datasheet for exact preparation.
  • For authoritative, item-specific limits (e.g., pH range, fill volumes), consult the CoA/Spec Sheet.

Quality and Grades

• Item-specific quality

  • Grade: BioReagent (from Product Data). This indicates suitability for laboratory research workflows in the life sciences. It does not imply clinical/diagnostic use.
  • USP designation in product name: Indicates the formulation aligns with the United States Pharmacopeia (USP) description for Bismuth Sulfite Agar Medium. For exact compliance and any lot-specific attributes (e.g., growth-promotion testing results), refer to the CoA/Spec Sheet.

• What BioReagent grade means (general)

  • Emphasis on consistent performance in biological assays and microbiological culture. Typical expectations include controlled bioburden in the dehydrated powder, reliable selectivity, and reproducible differential response when prepared as directed.

• Microbiological quality controls (literature/general)

  • Growth-promotion testing is commonly performed using challenge strains, e.g., recovery of Salmonella enterica (positive control) and inhibition of competing flora (e.g., certain coliforms, Gram-positives) to verify selectivity/differential performance. Specific strains and acceptance criteria are defined by pharmacopeial or internal SOPs and are lot-dependent.

• Stabilizers and additives

  • Not specified for this item; refer to CoA/Spec Sheet.

• Practical notes

  • Because selective components can be heat-labile, adherence to the recommended preparation method materially affects quality. Avoid autoclaving unless expressly allowed by the product’s instructions. Prepare fresh plates and protect from light to maintain dye and selective agent efficacy.

Reaction and Applications

As a culture medium, this product is not used as a reagent in chemical reactions. Its applications are microbiological.

• Primary applications (literature/general)

  • Selective and differential plating medium designed for the isolation of Salmonella spp. from complex samples in research, environmental monitoring, food microbiology studies, and pharmacopeial compendial testing workflows.
  • Differentiation principle: Many Salmonella reduce sulfur to H2S, which reacts with ferrous ions to produce black precipitates in and around colonies. Bismuth salts and brilliant green inhibit commensal Gram-positive flora and many Gram-negative competitors, enhancing selectivity.

• Practical tips

  • Prepare plates fresh and protect from light; prolonged storage reduces selectivity and indicator response.
  • Overheating can deactivate selective components; most formulations are heated just to boiling to dissolve, rather than autoclaved. Follow the product’s instructions exactly.
  • Mixed inocula from enrichment broths often produce more reliable recovery than direct plating for low-level targets; use streak isolation techniques to obtain well-separated colonies.

• Downstream use (general)

  • Presumptive colonies typically require confirmation by biochemical tests and/or molecular methods. Bismuth sulfite agar provides presumptive differentiation but is not confirmatory.

• Notable limitations

  • Some Salmonella strains may be inhibited or may not produce strong H2S under certain conditions; conversely, a few non-target organisms can produce H2S. Therefore, use as part of a broader workflow.

Reaction Conditions

Chemical reaction conditions are not applicable. However, preparation and incubation conditions strongly influence microbiological performance.

• Preparation conditions (literature/general)

  • Reconstitution: Suspend the dehydrated medium in purified water with vigorous stirring. Heat to near boiling to dissolve completely. Many bismuth sulfite agar formulations are not autoclaved due to heat-labile selectivity; follow the product’s instructions precisely.
  • Agar handling: Avoid prolonged boiling; do not overheat. Cool to approximately 45–50 °C before pouring plates to reduce condensation and preserve selectivity.

• Incubation conditions (literature/general)

  • Temperature: Typically 35–37 °C.
  • Atmosphere: Aerobic incubation is standard.
  • Time: 24–48 hours, monitoring for characteristic colony development (blackening due to H2S/Fe interaction). Some strains may require extended incubation.

• Performance variables

  • Sample matrix and pre-enrichment history influence recovery. Excess background flora may require parallel use of alternative selective agars.
  • Plate age and light exposure can diminish selectivity; prepare fresh for critical work.

For item-specific directions (e.g., exact mass per liter, target pH), Not specified for this item; refer to CoA/Spec Sheet.

Safety and Handling

• Item-specific hazard data

  • GHS classification, signal word, pictograms, H-statements: Not specified for this item; refer to the SDS.

• General safety considerations (literature/general for bismuth sulfite media)

  • Contains heavy metal salts (bismuth compounds) and an organic dye (brilliant green). Avoid inhalation of dust and contact with skin/eyes. Use in a fume hood when weighing if dusting may occur.
  • PPE: laboratory coat, safety glasses or face shield, and appropriate chemical-resistant gloves (e.g., nitrile). Use respiratory protection when airborne dust cannot be controlled.
  • Incompatibilities: Strong acids/bases may decompose components; oxidizers may affect the dye; sulfide/sulfite chemistry can be perturbed by oxidants. Keep dry; moisture uptake can cause clumping and performance changes.
  • Microbiological risk: The dehydrated medium is non-sterile. Once prepared and inoculated, plates contain viable microorganisms—treat all used media as biohazardous waste per institutional biosafety protocols.

• First aid (overview; defer to SDS)

  • Inhalation: Move to fresh air; seek medical attention if symptoms persist.
  • Skin/eye contact: Rinse with copious water for at least 15 minutes; remove contaminated clothing; obtain medical advice if irritation persists.
  • Ingestion: Rinse mouth; seek medical attention.

• Waste and decontamination

  • Autoclave inoculated plates/broths before disposal. Chemical disposal of unused dye- or heavy-metal–containing media should follow local regulations for hazardous waste.

Always consult the product-specific SDS for authoritative hazard and response information.

Solvent Selection

This product is a dehydrated microbiological medium intended to be reconstituted in purified water; organic solvent selection is not applicable.

• Item-specific guidance

  • Use high-quality water (distilled/deionized) for reconstitution. Item-specific conductivity/TOC limits are Not specified for this item; refer to CoA/Spec Sheet.

• Practical notes (literature/general)

  • Water quality influences selectivity and clarity. Residual chlorine/chloramine or high hardness can adversely affect performance; pre-treatment (e.g., activated carbon, deionization) is recommended.
  • Dissolution typically requires heating to near boiling with constant stirring to achieve uniform melting without localized overheating.
  • Do not add organic solvents; they can denature nutrients and destroy selectivity.

• Comparison within culture media (general)

  • For selective enrichment of Salmonella on plates, water-based agar systems such as Bismuth Sulfite Agar, XLD Agar, Hektoen Enteric Agar, and SS Agar are commonly used; choose based on sample matrix and regulatory method. These all reconstitute in water and differ in selective agents and indicators rather than solvent choice.

Storage and Reconstitution

• Item-specific storage and shipping

  • Storage conditions: Room temperature (from Product Data). Keep container tightly closed in a dry place; protect from light and moisture to preserve selective components.
  • Shipped in: Normal (from Product Data).

• Reconstitution (item-specific amounts/pH)

  • Exact mass-per-liter, target pH, and sterilization instructions: Not specified for this item; refer to CoA/Spec Sheet.

• General reconstitution guidance (literature/general)

  • Use freshly produced purified water (DI/RO) for reconstitution. Heat with stirring to achieve complete dissolution. Avoid autoclaving unless the product’s instructions permit it; many formulations are heat-sensitive. Cool to ~45–50 °C before pouring plates.

• Storage of prepared medium (literature/general)

  • Plates: Store inverted at 2–8 °C, protected from light, in sealed sleeves to prevent desiccation. Use as soon as practical; many labs target use within 1–2 weeks, subject to in-house qualification.
  • Broth (if prepared without agar for specialized workflows): Use promptly; the selectivity may change upon storage.

• Freeze–thaw guidance

  • Do not freeze the dehydrated powder. Freezing prepared plates is not recommended; it damages gel structure and performance.

• Research Use Note

  • For research use only (from Product Data). No clinical or diagnostic claims are made.

Structure and Identity

This product is a complex, dehydrated culture medium rather than a single defined compound. It is intended for the preparation of Bismuth Sulfite Agar plates compliant with USP methodology.

• Item-specific facts (from Product Data)

  • SKU: B1528474
  • Product name: Bismuth Sulfite Agar Medium (USP)
  • Grade: BioReagent
  • Storage conditions: Room temperature; shipped under normal conditions
  • CAS, InChIKey, SMILES, molecular formula, molecular weight: Not applicable for a multi-component medium; Not specified for this item; refer to CoA/Spec Sheet.

• Composition and identity (literature/general)

  • Bismuth sulfite agar is a selective and differential medium. Typical formulations include peptones/enzymatic digests, beef extract, glucose, bismuth salts (e.g., basic bismuth sulfite), ferrous sulfate, sodium phosphate (buffer), and the dye brilliant green. Exact proportions vary by standard/brand; consult the USP monograph or the item’s CoA for definitive composition.
  • Structural features (conceptual): mixture of inorganic salts (bismuth, iron, phosphate, sulfite), organic nutrients (peptides, carbohydrates), and an organic dye. No single molecular structure applies.

• Functional identity (literature/general)

  • Designed for the selective isolation and presumptive differentiation of Salmonella spp. from complex samples by combining selective agents (bismuth, brilliant green) with indicators (H2S production visualized via ferrous ions).

Because this is a mixture, single-compound identifiers (SMILES, InChI, ring systems, stereochemistry) are not applicable.

Synthetic Utility

Not applicable. This product is a formulated microbiological growth medium and is not typically used as a reagent or building block in chemical synthesis.

• Guidance
  • For chemical synthesis applications (e.g., as sulfur source, metal salt reagent, or dye), procure single-component reagents of defined purity and known specifications rather than a complex culture medium.
  • If your work involves surface growth studies, biofouling tests, or microbial corrosion research, this medium can provide a selective platform for culturing relevant organisms, but it remains outside conventional synthetic chemistry utility.

Target Specificity

This section typically applies to antibodies or affinity reagents; for a culture medium, “specificity” refers to microbial selectivity.

• Selectivity profile (literature/general)

  • Intended target organisms: Salmonella spp., including many serovars that produce H2S on agar and tolerate the inhibitory system.
  • Inhibition spectrum: Many Gram-positive bacteria and a portion of Enterobacteriaceae (e.g., coliforms) are suppressed by the combination of bismuth salts and brilliant green.
  • Differential readout: H2S-positive colonies often appear with black centers or entirely black due to ferrous sulfide precipitation; the surrounding medium may darken along streak lines.

• Caveats

  • Some Salmonella strains may be inhibited, and some non-target organisms (e.g., Proteus, Citrobacter) can form H2S and resemble target colonies. Use confirmatory tests.

No antibody clone/isotype/species reactivity applies to this product.

Preguntas frecuentes

How should this product be stored?

Store at room temperature.