Hektoen Enteric Agar Medium (USP) - BioReagent

Cat. No.: H1528630

GRADE & PURITY BioReagent

Storage

Room temperature

Shipped In

Normal

Panoramica

For selective isolation of intestinal bacteria. HE agar medium preparation method: Weigh 72.6 g of this product in 1 L of distilled or deionized water (the volume may be scaled up or down proportionally), heat and boil for 1 minute to completely dissolve, pour into plates, and set aside for use.

Specifications

Specifiche e purezza

BioReagent

Condizioni di conservazione di stoccaggio

Room temperature

Spedito in

Normal

Grado

BioReagent

Product Line

biological_products

Application Protocols

No antibody-based applications (WB, IHC, IF, FC) apply. The following is general microbiology guidance (literature) for research/QC labs; follow your validated SOP for exact steps.

• Plate preparation (overview):
  1. Weigh dehydrated medium as specified by your method (Not specified for this item; refer to CoA/Spec Sheet). Disperse in purified water with stirring.
  2. Heat to dissolve completely. Adjust volume if needed.
  3. Sterilize by autoclaving per validated cycle. Cool to a suitable pour temperature and pour into sterile Petri dishes. Allow to solidify and dry surface to reduce excess moisture.
• Inoculation and incubation:
  • Streak specimens using aseptic technique. Incubate plates in an appropriate atmosphere and temperature per the method.
  • Avoid stacking patterns that impede heat transfer; control plate condensation.
• Reading results (presumptive, literature):
  • Lactose/sucrose/salicin fermenters: yellow to orange colonies/halos from acid production.
  • Non-fermenters (e.g., Shigella): green to blue-green colonies.
  • H2S producers (e.g., many Salmonella): black-centered colonies due to FeS.
• Quality controls:
  • Include positive and negative control strains per SOP to verify selectivity and differential performance each preparation.

Dispose of used plates as biohazardous waste after appropriate decontamination.

Biological Roles

This product itself has no biological role as a metabolite or biomolecule; rather, it is a tool to interrogate microbial physiology in mixed populations (research context).

• Functional concept (literature):
  • Selective agents (bile salts) inhibit many Gram-positive bacteria, enriching for enteric Gram-negative rods.
  • Differential substrates (lactose, sucrose, salicin) probe carbohydrate fermentation pathways; acid generation drives indicator color changes, reflecting metabolic capacity.
  • Thiosulfate reduction tests sulfur metabolism; H2S production yields FeS precipitate with ferric ions.
• Research insights supported by HEA:
  • Phenotypic profiling of enteric isolates regarding carbohydrate utilization and sulfur reduction.
  • Comparative studies of stress tolerance: recovery efficiencies on HEA versus non-selective media can indicate physiological robustness.
  • Preliminary segregation of colonies for downstream genotyping, antimicrobial susceptibility testing (on separate, appropriate media), or metabolic assays.

HEA outputs are presumptive and phenotype-based; final organism identification should integrate additional biochemical, serological, or molecular methods as appropriate to the study design.

Buffer Applications

Not a standalone buffer system. Hektoen Enteric Agar includes internal buffering capacity (from its composite ingredients) to maintain the medium’s working pH during incubation (literature), but it is not used for preparing defined buffer solutions or electrophoresis buffers.

For buffer preparation needs, use defined buffer reagents (e.g., phosphate, Tris, MOPS) specified by your protocol.

Green Alternatives

As a dehydrated agar medium, HEA already avoids many solvent-intensive steps common in chemical synthesis. Sustainability considerations focus on water/energy use, waste minimization, and safer dye/indicator handling.

• Environmental aspects (general):
  • The product is reconstituted in water and sterilized by heat; principal impacts are energy for autoclaving and disposal of biohazardous agar plates.
  • Some components (bile salts, dyes) can contribute to colored effluents; used plates must be decontaminated before disposal per local regulations.
• Greener practice recommendations (literature/general):
  • Right-size batch preparation to minimize expired/unused plates.
  • Use energy-efficient autoclave cycles validated for the load; avoid oversterilization.
  • Consider reusable glassware and refillable plate systems where validated, to reduce single-use plastics.
  • Segregate biohazard waste efficiently and explore validated on-site decontamination to reduce transport emissions.
• Alternative media considerations:
  • Depending on the organism panel and selectivity needed, XLD agar or chromogenic agars may reduce confirmation steps by providing higher discrimination; trade-offs include different dye chemistries and cost.

Choose media and workflows that achieve required performance with the lowest resource footprint while meeting regulatory and quality objectives.

Pharmaceutical Uses

No therapeutic use is implied. In a pharmaceutical and personal care product QA/QC context, Hektoen Enteric Agar (USP) is used as a culture medium within microbiological test workflows (research and quality control use only).

• Role in compendial-style testing (general, literature):
  • Employed for the selective/differential isolation of specified enteric organisms from non-sterile product examinations, ingredient testing, and environmental monitoring, when called for by the method.
  • Its USP designation indicates suitability for use where HEA is referenced in pharmacopeial or validated internal methods; actual compliance must be verified per lot via CoA and growth-promotion testing.
• Practical considerations for QC labs:
  • Document lot numbers and perform incoming growth promotion tests with compendial challenge strains per your SOP.
  • Prepare plates with water quality and sterilization parameters that meet site validation standards.
  • Maintain traceability from medium preparation through incubation and result recording to support data integrity.

Always consult your site’s validated SOPs and current pharmacopeial chapters for method-specific requirements.

Physical Properties

Because Hektoen Enteric Agar is a complex, dehydrated mixture, conventional pure-compound properties (bp, mp, density, logP, refractive index) are not applicable.

• Aggregate state: Dehydrated powder (general for culture media; specific appearance Not specified for this item; refer to CoA/Spec Sheet.)
• Solubility: Designed to dissolve/disperse in water upon heating (literature, typical for dehydrated agar media).
• Final medium state: Firm gel upon cooling after sterilization due to agar (literature).
• pH (of prepared medium, literature): Typically near neutral to slightly alkaline to support selectivity and indicator performance; exact value is product-specific. Not specified for this item; refer to CoA/Spec Sheet.
• Color (prepared plates, literature): Greenish medium; fermenters produce yellow-orange colonies/halos; H2S producers yield black-centered colonies due to FeS. Not specified for this item; refer to CoA/Spec Sheet.
• Stability: Stable as a dry blend when kept dry at room temperature; hydrated medium is best used fresh or stored refrigerated for short periods (general microbiology practice; see Storage & Reconstitution).

No pure-substance thermodynamic or spectroscopic constants are reported because they are not meaningful for this mixture.

Quality and Grades

• Item-specific grade: BioReagent (as provided). This denotes suitability for laboratory research applications, including microbiology workflows, with attention to consistency and low levels of inhibitory contaminants relative to general industrial grades.
• USP designation: “(USP)” signifies alignment with pharmacopeial expectations for use in compendial microbiology. In quality control laboratories, HEA is commonly employed in workflows described in pharmacopeias (e.g., for isolation/detection of specified organisms) when HEA is named; actual compendial compliance must be verified against the current monograph/method and the lot CoA.
• What to expect in the CoA/Spec Sheet (typical for media; item-specific values not provided here):
  • Growth promotion test results with defined strains (e.g., recovery and characteristic reactions for Salmonella/Shigella; partial or complete inhibition of certain Gram-positives).
  • pH of reconstituted medium at a defined temperature.
  • Appearance of dehydrated powder and prepared medium.
  • Sterility test results and lot traceability.
• Stabilizers/preservatives: Not specified for this item; refer to CoA/Spec Sheet. Dehydrated media are typically preservative-free dry blends (literature).
• Practical guidance:
  • Use validated preparation conditions (water quality, heating/sterilization, pour temperature) per method requirements to achieve the selectivity/differential performance intended for HEA.
  • For regulated testing, document lot numbers and verify growth-promotion performance on receipt and after significant storage intervals.

Reaction and Applications

Chemical reaction applications are not applicable; this product is a selective/differential microbiological medium rather than a chemical reagent. The following summarizes laboratory applications (literature, research use):

• Primary application: Isolation and differentiation of enteric bacteria from mixed samples based on fermentation of lactose/sucrose/salicin and hydrogen sulfide (H2S) production.
  • Fermenters produce acid, shifting indicators to yellow–orange colony coloration/halos.
  • Non-fermenters (e.g., Shigella) remain green to blue-green.
  • H2S producers (e.g., many Salmonella) form black-centered colonies due to FeS precipitate from thiosulfate reduction.
• Use cases in research and QA/QC:
  • Environmental monitoring, food/water microbiology studies, and non-clinical product quality assessments where recovery and presumptive differentiation of enteric organisms are desired.
  • As part of multi-plate workflows: streak samples on HEA alongside less selective media to improve recovery of stressed organisms.
• Practical tips (literature):
  • Confirm presumptive identifications with biochemical/serological/molecular tests; HEA provides presumptive differentiation only.
  • Plate quality matters: correct pour depth, surface dryness, and incubation parameters impact colony morphology and selectivity.
  • Over-incubation can blur differential reactions; read plates at method-specified intervals.

Note: For regulated methods, follow the compendial or validated SOP specific to your laboratory.

Reaction Conditions

Not applicable to chemical reactions. For laboratory preparation conditions (literature, general microbiology practice):

• Reconstitution: Disperse the dehydrated medium in purified water with stirring; heat to dissolve agar fully. Avoid prolonged boiling.
• Sterilization: Typically achieved by autoclaving using validated time/temperature cycles per your SOP. Do not add heat-labile supplements before sterilization unless specified.
• Pouring plates: Cool molten medium to a pour temperature that minimizes condensation while maintaining fluidity; pour into sterile plates to an appropriate depth and allow to solidify.
• Incubation: Use method-specified temperature and duration; deviations impact selectivity and colony morphology.

Exact preparation parameters (e.g., grams per liter, autoclave time/temperature) are method- and product-specific and are Not specified for this item; refer to CoA/Spec Sheet and your validated SOP.

Safety and Handling

• GHS classification, signal word, pictograms, H-statements: Not specified for this item; refer to CoA/Spec Sheet and SDS for authoritative safety data.
• General hazards (mixture):
  • Dehydrated media may generate nuisance dust; avoid inhalation and eye contact. Some dye components (e.g., acid fuchsin) may stain and can be irritant (literature/general).
  • After use with microorganisms, plates are biohazardous and must be handled and disposed of as regulated biological waste per institutional and local regulations.
• PPE recommendations (general good lab practice):
  • Lab coat, safety glasses, and appropriate gloves; use dust control measures and weigh in a fume hood or ventilated enclosure if dusting is significant.
• Handling/operation cautions:
  • When preparing medium, avoid burns from hot liquids and autoclaves. Use heat-resistant gloves and face protection as needed.
  • Prevent contamination by using aseptic technique when pouring plates and inoculating.
• Incompatibilities (general):
  • Keep dry blend away from strong oxidizers/acids/bases that could degrade organic components; avoid moisture uptake before use.
• First aid (overview; defer to SDS):
  • Eyes/skin: Rinse with water. Inhalation: move to fresh air. Ingestion: rinse mouth. Seek medical attention as needed; provide SDS to responders.

Always consult the SDS and institutional biosafety procedures before use. For research use only.

Solvent Selection

This product is a dehydrated culture medium formulated for dissolution/dispersion in water; organic solvent selection is not applicable.

• Solvent: Purified water (e.g., ASTM Type I/II or per compendial/QA requirements) is used for reconstitution (literature/general practice).
• Dissolution behavior (literature):
  • The blend disperses in cold water and typically requires heating to near boiling to fully dissolve agar and achieve clarity before sterilization.
  • Avoid excessive boiling that can degrade carbohydrates and indicators.
• Compatibility notes:
  • High ionic strength or non-aqueous solvents are not appropriate. Use only water that meets your method’s specification to avoid inhibitory contaminants (e.g., residual chlorine, heavy metals).
• When to choose HEA vs alternatives (literature):
  • Select HEA for selective/differential isolation of enteric pathogens based on lactose/sucrose/salicin fermentation and H2S production.
  • Alternatives include XLD agar, SS agar, and MacConkey agar; each has different selectivity and readouts. HEA offers a broader range of carbohydrate substrates and a dual-indicator system that can enhance differentiation.

For quantitative preparation details (e.g., grams per liter), follow your validated SOP or the lot-specific label/CoA.

Storage and Reconstitution

• Storage (item-specific): Room temperature (as provided). Shipments are under normal conditions. Keep tightly closed in a dry place to prevent caking and premature hydration.
• Shelf life: Not specified for this item; refer to CoA/Spec Sheet. Use oldest acceptable lot first (FIFO) and monitor for caking or discoloration.
• Reconstitution (general, literature):
  • Use purified water meeting your lab’s or compendial specifications. Disperse powder with stirring; heat until agar is fully dissolved. Avoid scorching or overboiling that can affect indicator performance.
  • Sterilize using a validated autoclave cycle appropriate for the volume. If supplements are required by your method, add them aseptically after sterilization and cooling to the recommended temperature.
  • Pour plates at a controlled temperature to minimize condensation. Allow to solidify on a level surface; store prepared plates protected from light at refrigeration temperature if not used immediately, per SOP.
• Freeze–thaw: Not applicable to the dehydrated powder. Avoid freezing the prepared agar if plate integrity and performance must be preserved.

For exact preparation parameters (e.g., mass per liter, target pH), and any lot-specific instructions, Not specified for this item; refer to CoA/Spec Sheet.

Structure and Identity

Hektoen Enteric Agar (HEA) is a complex, dehydrated microbiological culture medium; it is not a single defined chemical entity.

• Item-specific identifiers
  • CAS: Not specified for this item; refer to CoA/Spec Sheet.
  • InChIKey / SMILES: Not applicable (complex mixture).
  • Molecular formula / molecular weight: Not applicable to mixtures; Not specified for this item; refer to CoA/Spec Sheet.
• Composition and functional components (literature, typical for HEA)
  • Peptones/yeast extract: supply nitrogen, vitamins, and growth factors.
  • Bile salts: selective agents to inhibit many Gram-positive organisms.
  • Carbohydrates: typically lactose, sucrose, and salicin for differential fermentation.
  • Sodium thiosulfate + ferric ammonium citrate: H2S detection system (black precipitate of FeS when reduced sulfur is produced).
  • pH indicators: bromothymol blue and acid fuchsin provide color contrast based on acid production.
  • Agar: gel-forming polysaccharide providing a solid surface.
• Structural/functional description (general)
  • A tan-to-greenish dehydrated powder blend (appearance not specified for this item) that, when reconstituted in water and sterilized, yields a selective and differential solid medium for the isolation and differentiation of enteric bacteria (e.g., Salmonella and Shigella) based on carbohydrate fermentation and H2S production.
• USP designation
  • “USP” indicates the formulation aligns with pharmacopeial expectations for use in compendial microbiology (general guidance; see Quality & Grades).

Synthetic Utility

Not applicable. Hektoen Enteric Agar is a microbiological culture medium and is not used as a reagent or intermediate in chemical synthesis, catalysis, or materials fabrication.

For chemical synthesis needs, consult solvent and reagent sections of the catalog for appropriate building blocks, catalysts, and reaction media.

Target Specificity

Antibody/antigen target specificity does not apply to this product.

General note (literature): HEA is designed to be selective for enteric Gram-negative bacteria and differential for fermenters and H2S producers. Organism-level “specificity” is presumptive and must be confirmed with appropriate identification methods.