Agar Medium J (Deoxycholate Citrate Agar) (EP) - BioReagent

Cat. No.: A1528672

GRADE & PURITY BioReagent

Storage

Room temperature

Shipped In

Normal

개요

For selective isolation of Salmonella. Preparation method: Weigh 69.5 g of this product in 1 L of purified water, stir and heat to boiling for 1 minute to completely dissolve, cool to 50–55°C and pour into plates.

Specifications

사양 및 순도

BioReagent

보관 조건

Room temperature

배송

Normal

등급

BioReagent

Product Line

생물 제품

Application Protocols

The following is generalized, literature-based guidance for deoxycholate citrate agar. For this specific item, preparation factors and acceptance criteria are Not specified for this item; refer to CoA/Spec Sheet and follow your laboratory SOP.

• Materials: Dehydrated Agar Medium J powder, purified water, heat source, autoclave, sterile Petri dishes.
• Preparation (literature typical):
  1. Weigh the recommended mass of dehydrated medium per liter of water (many DCA formulations are used at ~50–55 g/L; confirm for this item).
  2. Suspend in cold water with stirring. Heat to boiling to dissolve completely; avoid scorching.
  3. Sterilize as directed (commonly 121 °C for ~15 min unless otherwise specified). Excess autoclaving can reduce selectivity.
  4. Cool to 45–50 °C. If necessary, re-mix gently to ensure homogeneity while minimizing bubbles.
  5. Pour 20–25 mL per 90 mm plate. Allow to solidify; dry plates if surface moisture is excessive.
• Quality controls: Perform Growth Promotion Testing—challenge with compendial strains (e.g., Salmonella spp. for growth; representative Gram-positives for inhibition) and verify expected differential reactions. Record pH of cooled medium.
• Use: Streak or spread inoculum onto the plate surface. Incubate inverted plates at 35–37 °C for 18–24 h (or per method). Interpret colony color/morphology and H2S reaction; follow up with confirmatory identification.
• Disposal: Autoclave used plates and leftover medium before disposal according to institutional biosafety guidelines.

Biological Roles

This section addresses how the formulation components function biologically during culture (general literature context).

• Selectivity: Bile salts (e.g., sodium deoxycholate) and citrate inhibit Gram-positive bacteria and many non-target Gram-negative species by disrupting membrane integrity and chelating divalent cations critical for some microbes.
• Differential indicators: Fermentable carbohydrates (often lactose) combined with a pH indicator (e.g., neutral red) reveal acid production by fermenters as colony color changes, enabling rapid presumptive differentiation.
• H2S system: Sodium thiosulfate may be reduced by certain bacteria to H2S, which reacts with ferric ions to form insoluble iron sulfide, producing black-centered colonies.
• Agar matrix: Provides a hydrated porous gel facilitating diffusion of nutrients and selective agents while maintaining distinct colony morphology and isolation.
• Use case: Together these roles support isolation and initial characterization of enteric organisms from mixed microbiota. Final identification typically requires confirmation tests (biochemical panels, MALDI-TOF, molecular assays).

Buffer Applications

Not typically applicable. This product is a complete selective/differential culture medium rather than a defined buffering system. While prepared media possess inherent buffering capacity from their constituents, it is not used as a laboratory buffer. For buffering needs, employ defined buffer systems (e.g., phosphate, HEPES) appropriate to your application.

Green Alternatives

From a green chemistry perspective, dehydrated agar media are water-based and used at ambient pressure/temperatures for pouring and incubation. Considerations focus on waste minimization, energy use, and selectivity balance rather than solvent substitution.

Comparison of selective enteric media (literature, generalized):

• Deoxycholate Citrate Agar (this product): Balanced selectivity via bile salts and citrate; differential via carbohydrate and H2S system. Good for general enteric screening. Energy use limited to heating/autoclaving and incubation.
• XLD Agar: Uses xylose, lysine, deoxycholate; often offers clearer differentiation of Salmonella vs. coliforms; similar aqueous preparation and waste profile.
• Hektoen Enteric Agar: Higher bile salts and dyes increase selectivity; may reduce background growth further but can suppress stressed targets.
• SS Agar: Strong selectivity; can inhibit some Salmonella strains; use judiciously to avoid false negatives.

Greener practice tips:

• Prepare only the volume needed; avoid overproduction of plates.
• Use energy-efficient autoclave cycles validated for sterility assurance.
• Segregate biohazard waste and autoclave prior to disposal; minimize single-use plastics where validated (e.g., reusable glass plates/trays where allowed).

Pharmaceutical Uses

No therapeutic use is implied. For research and quality control only.

• EP context (general, literature): Deoxycholate citrate agar is used in pharmacopeial microbiological quality testing workflows, such as detection and isolation of specified microorganisms from non-sterile products or environmental monitoring samples, following EP chapters on microbial enumeration and specified microorganism tests. Laboratories must perform suitability testing (recovery/inhibition) with compendial strains.
• Role in manufacturing/QC:
  • Environmental monitoring and investigation of water/utility systems for enteric contaminants.
  • In-process and finished product testing where selective recovery of enteric bacteria is required by internal or compendial methods.
• Documentation: Each lot should be qualified via Growth Promotion Testing (GPT) and documented under GMP/GLP as applicable. Item-specific acceptance criteria are Not specified for this item; refer to CoA/Spec Sheet.
• Packaging formats: Dehydrated powder is typically reconstituted to prepare poured plates within the facility; ready-to-use plates, if needed, are sourced separately per site SOPs.

Physical Properties

Item-specific physicochemical specifications are not provided in the Product Data. For authoritative values and tolerances, consult the CoA/Spec Sheet for this lot.

• Appearance: Not specified for this item; refer to CoA/Spec Sheet. (Typically a free‑flowing, homogeneous dehydrated powder; literature.)
• Solubility: Designed to be reconstituted in purified/distilled water to prepare plates (literature). Final clarity may be slightly opalescent due to selective agents and indicators (literature).
• pH (prepared medium): Not specified for this item; refer to CoA/Spec Sheet. (Typically near neutral in the finished medium; literature.)
• Melting/boiling point, density, refractive index, logP, pKa: Not applicable to a complex dehydrated medium; Not specified for this item; refer to CoA/Spec Sheet.
• Agar gelation (literature): Agar gels upon cooling below ~40–45 °C and remelts above ~80–90 °C; these are general properties of agar gels and influence pour temperatures.
• Color response (literature): Differential indicators in deoxycholate citrate systems typically yield colored colonies/halos for lactose fermenters vs. non‑fermenters, and H2S producers may form black centers due to iron sulfide.

Quality and Grades

• Grade: BioReagent (from Product Data): Indicates suitability for laboratory and microbiological research workflows. Typical expectations include consistent performance in culture applications and controlled bioburden of the dehydrated medium.
• EP designation (from Product Name): The formulation aligns with European Pharmacopoeia usage as a selective/differential medium for specified microbial tests (e.g., detection/isolation of enteric organisms). EP alignment supports use in pharmacopeial quality control workflows, subject to verification/qualification in your lab.
• What EP implies (general, literature): Reproducibility of selectivity/differential performance against defined test strains, and preparation/use consistent with EP chapters for microbiological quality (users must confirm compliance via growth promotion and suitability tests).
• Lot-specific controls: Growth Promotion Testing (GPT), pH of prepared medium, sterility of uninoculated plates/broth, water activity of powder. Item-specific acceptance criteria are Not specified for this item; refer to CoA/Spec Sheet.
• Stabilizers/defomers/indicators: Selective and indicator components are intrinsic to the formulation; no external stabilizer is specified in Product Data. For any additives, refer to CoA/Spec Sheet.
• Practical note: Qualify each lot for critical assays (e.g., Salmonella/Shigella recovery) under your SOPs. Document GPT with compendial strains where applicable to your use case.

Reaction and Applications

Classical chemical reaction frameworks (e.g., catalysis, synthesis) are not applicable to this product. It is used in microbiological culture rather than in chemical transformations.

• Relevant applications (microbiology, literature):
  • Selective isolation and differentiation of enteric bacteria from clinical, food, environmental, and pharmaceutical samples.
  • Enrichment-to-plating workflows for detection of Salmonella spp. and related organisms, following compendial or internal SOPs.
  • Confirmation/biotyping steps in tandem with complementary media.
• For procedural details (media preparation, pouring, incubation, readout), see Application Protocols.

Reaction Conditions

Classical chemical reaction conditions do not apply. For microbiological preparation and use (literature guidance; verify with your SOP and CoA/Spec Sheet):

• Reconstitution: Dissolve the dehydrated medium in purified water with heating and agitation until fully dissolved. Avoid localized overheating or charring.
• Sterilization: Many selective agars are sterilized by autoclaving (e.g., 121 °C). Some formulations may recommend boiling to dissolve followed by limited autoclaving to preserve selectivity. Follow the manufacturer’s instructions for this item (Not specified; refer to CoA/Spec Sheet).
• Pouring: Cool molten agar to approximately 45–50 °C before pouring plates to minimize condensation and thermal degradation of indicators (literature).
• Incubation: Typical incubation for enteric bacteria is 35–37 °C for 18–24 h, adjusted per method and organism (literature).
• Readout: Evaluate colony morphology, color changes, and H2S production. Confirm presumptive results with secondary tests.

All numeric parameters above are general literature guidance and should be optimized/qualified in your laboratory.

Safety and Handling

Always review the Safety Data Sheet (SDS) for definitive hazard classifications and protective measures for your specific lot.

• GHS classification / Signal word / H‑statements / Pictograms: Not specified for this item; refer to SDS.
• General hazards (literature/best practice): Dehydrated culture media may cause respiratory irritation as dust; some selective components (e.g., bile salts, dyes) can irritate skin/eyes. Avoid generating and inhaling dust.
• PPE: Laboratory coat, safety glasses/goggles, and appropriate gloves. Use a dust mask/respirator if airborne dust may be generated during handling or weighing, per risk assessment.
• Engineering controls: Work in a clean area. Use local exhaust or a biosafety cabinet when handling live cultures on prepared plates.
• Incompatibilities (general): Avoid contact with strong oxidizers and strong acids/bases that could degrade organic components. Keep dry until use; moisture uptake leads to clumping and performance loss.
• First aid (overview): Eye/skin contact—rinse with water for several minutes; remove contaminated clothing. Inhalation—move to fresh air. Ingestion—rinse mouth; seek medical advice. Follow site SOPs and SDS guidance.
• Microbiological risk: Once reconstituted and inoculated, plates may contain viable pathogens. Handle according to biosafety level requirements (e.g., BSL‑2 for enteric pathogens) and autoclave waste before disposal.

Solvent Selection

This product is a dehydrated culture medium intended to be reconstituted with water; organic solvent selection is not typically applicable.

• Primary diluent (applicable): High-purity water (distilled/deionized) for preparing the agar medium (literature). Avoid hard or highly alkaline water that can alter selectivity or indicator response.
• Polarity/miscibility: Not relevant; the final system is an aqueous gel matrix formed by agar on cooling.
• When to choose this medium (general guidance): Use when selective isolation of enteric Gram-negative bacteria is required, leveraging bile salts and citrate inhibition of Gram-positive and some coliforms, with differential readouts via carbohydrate fermentation and H2S indication.
• Alternatives (contextual): Other aqueous media such as XLD, Hektoen Enteric, SS Agar, MacConkey Agar may be selected based on target organisms and required stringency (literature). See Green Alternatives for comparative notes.

Storage and Reconstitution

• Storage conditions (from Product Data): Room temperature. Keep container tightly closed in a cool, dry place. Protect from humidity to prevent clumping and loss of performance.
• Shipping (from Product Data): Shipped at ambient conditions (Normal).
• Shelf life: Not specified for this item; refer to CoA/Spec Sheet. Use opened containers promptly and reseal to limit moisture uptake.
• Reconstitution (literature guidance): Suspend the recommended mass of dehydrated medium in purified water with stirring, heat to dissolve, and sterilize per instructions for this product (Not specified; refer to CoA/Spec Sheet). Cool to ~45–50 °C before pouring plates to preserve selectivity and indicator function.
• Freeze–thaw: Not applicable to dehydrated powdered media. Avoid freezing the powder; store dry at room temperature as directed.
• Research use note (from Product Data): For research use only.
• Post-preparation storage: Store poured plates in sealed sleeves at 2–8 °C, protected from light to preserve indicators; allow plates to equilibrate to room temperature and surface to dry before use (literature). Validate maximum hold time for plates under your SOP.

Structure and Identity

This product is a complex, dehydrated microbiological culture medium, not a single defined chemical substance.

• Product name: Agar Medium J (Deoxycholate Citrate Agar) (EP)
• SKU: A1528672
• Type: Selective and differential agar medium (dehydrated powder) for enteric bacteria
• Regulatory alignment: EP (European Pharmacopoeia) compliant medium class (general; see Quality & Grades)
• Grade: BioReagent (from Product Data)
• CAS / CID / InChIKey / SMILES: Not applicable to mixtures of undefined composition; Not specified for this item; refer to CoA/Spec Sheet.
• Molecular formula / Molecular weight: Not applicable for a mixture; Not specified for this item; refer to CoA/Spec Sheet.
• Structural features (general knowledge, literature): Deoxycholate citrate agar typically contains a mixture of peptones/enzymatic digests, bile salt (sodium deoxycholate), sodium citrate, thiosulfate, ferric salt, carbohydrate (commonly lactose), pH indicator (e.g., neutral red), and agar as the gelling agent. These components collectively impart selectivity (bile salts and citrate) and differential responses (carbohydrate fermentation color change; H2S indication via thiosulfate/iron).
• 2D structure description: Not applicable; the product is a formulation containing multiple organic and inorganic constituents without a single defined molecular structure.

Synthetic Utility

Not applicable. This product is not a chemical building block or reagent for synthesis; it is a formulated microbiological medium used to culture microorganisms. For chemical transformations, refer to specific reagents and solvents designed for synthetic applications.

Target Specificity

Not an antibody or affinity reagent. No antigen/epitope specificity applies. In a microbiological sense (literature), the medium exhibits functional selectivity toward enteric Gram-negative bacteria through bile salts and citrate inhibition, but this is not “target specificity” in the immunochemical sense.