Potato Dextrose Agar (USP) - BioReagent

Cat. No.: P1528369

GRADE & PURITY BioReagent

Storage

Room temperature

Shipped In

Normal

Panoramica

For mold and yeast enumeration. Preparation method: Weigh 45.0 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

Specifiche e purezza

BioReagent

Condizioni di conservazione di stoccaggio

Room temperature

Spedito in

Normal

Grado

BioReagent

Product Line

Prodotti biologici

Application Protocols

General protocols (literature/best practice; adapt to your SOPs and the product label):

1. Preparation of PDA plates

• Weigh the manufacturer‑specified mass per liter (commonly ~39 g/L; verify label/CoA) into a flask with appropriate headspace.
• Add purified water and swirl to suspend. Heat with stirring until fully dissolved (avoid boiling over).
• Autoclave at 121 °C for 15 min. Cool to 45–50 °C.
• Optional: Add sterile antibiotic or 10% tartaric acid for selective applications. Mix gently.
• Aseptically pour 18–25 mL per 90–100 mm plate. Allow to solidify. Store inverted at 2–8 °C in sealed bags if preparing in advance (time limits per SOP).

2. Spread‑plate enumeration of yeasts/molds

• Prepare serial dilutions of sample in sterile diluent (e.g., peptone water).
• Pipette 0.1 mL onto the surface of dried PDA plate; spread with a sterile spreader.
• Incubate plates inverted at 25–30 °C for 3–5 days (organism dependent). Count colonies (25–250 CFU/plate target).

3. Pour‑plate method (when appropriate)

• Mix 1 mL inoculum with 15–20 mL molten PDA (~45 °C), swirl gently, allow to set, and incubate as above.

4. Maintenance of fungal stocks

• Streak isolate on PDA; incubate to obtain well‑separated colonies.
• For short‑term storage, refrigerate sealed plates/slants; for long‑term, transfer to cryopreservation per organism‑specific guidance.

Always verify acceptance criteria, organism panels, and incubation conditions per pharmacopeial/ISO standards as applicable.

Biological Roles

Potato Dextrose Agar (USP) is not a biomolecule but a nutritional matrix designed to support growth of eukaryotic microorganisms, primarily fungi and yeasts. Its components contribute distinct biological functions (literature/general):

• Dextrose (glucose): Central carbon source feeding glycolysis and downstream pathways (e.g., TCA cycle, fermentation). Supports rapid ATP generation and biomass accumulation in Saccharomycetes and filamentous fungi.
• Potato infusion/derivatives: Supplies amino acids, minerals (e.g., K, Mg, P), and vitamins that serve as cofactors for enzymatic processes (e.g., transamination, nucleotide biosynthesis). Complex nutrients often enhance sporulation/conidiation.
• Agar matrix: Provides a biocompatible, largely inert polysaccharide scaffold that allows colony isolation and diffusion‑limited growth; agar itself is minimally metabolized by most fungi and yeasts.

Microbiological behavior on PDA (general observations):

• Many fungi exhibit robust mycelial expansion and pigment/secondary metabolite production on PDA, aiding morphological identification.
• Yeasts typically form convex, smooth colonies; fermentative species may acidify the local medium.
• The mildly acidic pH (~5.6) reduces growth of numerous bacteria, enriching for fungal populations during environmental sampling.

Note: Composition is intentionally non‑selective for fungi; selectivity can be increased by acidification or by supplementing antibiotics (e.g., chloramphenicol) according to institutional approvals and applicable regulations.

Buffer Applications

Potato Dextrose Agar (USP) is not a buffering system and is not used to prepare analytical buffers. Its intrinsic buffering capacity is low; rather, it is formulated to achieve an acidic pH favorable to fungi.

• Typical finished pH: ~5.6 (literature/general), set by formulation rather than a discrete buffer pair.
• If a precise buffered environment is required (e.g., enzyme assays), prepare a separate defined buffer and, where appropriate, use a compatible liquid medium instead of agar.

For pH‑selective cultivation of fungi, see Reaction Conditions and Application Protocols for optional post‑sterilization acidification guidance.

Green Alternatives

Green chemistry considerations are limited for a prepared culture medium; nevertheless, laboratories can adopt practices that reduce environmental impact while maintaining microbiological performance.

• Resource efficiency (general):
  • Prepare only the volume needed to minimize disposable plate waste.
  • Use reusable glass media bottles and autoclavable glass Petri dishes where biosafety policies permit.
  • Optimize autoclave loads/cycles to reduce energy and water consumption.
• Alternative media choices (contextual, literature/general):
  • When specific nutrients are unnecessary, a defined minimal medium can reduce biological load in waste streams; however, growth and sporulation of many fungi may be compromised compared with PDA.
  • For environmental isolations focused on diversity rather than biomass, dilute PDA (e.g., half‑strength) can decrease resource use per plate and reduce fast‑growing species dominance.
• Waste management:
  • Segregate biohazard waste; favor steam sterilization over chemical disinfectants when feasible to minimize chemical disposal.
  • Composting of agar-containing waste is generally not permitted due to biohazard concerns; follow institutional biosafety disposal rules.

Trade‑offs:

• PDA’s performance for fungi/yeasts is often superior to leaner or defined media. Greener alternatives may reduce growth or alter community representation. Validate any substitution for your application before broad implementation.

Pharmaceutical Uses

Context in pharmaceutical/biotech manufacturing (no therapeutic claims):

• Microbiological Quality Control (QC): PDA (USP) is widely used for growth promotion and enumeration of yeasts and molds in accordance with pharmacopeial microbiology chapters (e.g., USP <61>, <62>, <71> contexts for suitability/growth promotion—literature/general). The USP designation indicates the formulation is intended to meet compendial expectations; verify with CoA.
• Environmental Monitoring (EM): Suitable for routine monitoring of controlled environments where fungal bioburden is tracked; can be used as settle plates or contact plates when prepared appropriately.
• Raw Material/Water Testing: Used for recovery of fungi/yeasts from purified water systems and incoming raw materials, aligning with vendor qualification and release testing SOPs.
• Antifungal Agent Manufacturing Support: Employed for maintaining reference cultures, preparing inocula, or preliminary screens prior to standardized potency/assay media.

Operational notes (general):

• Adoption in GMP environments requires documented growth promotion testing per lot/batch of prepared plates/media and traceability to the dehydrated medium’s CoA.
• Supplements (e.g., antibiotics, neutralizers) must be qualified for intended use and added aseptically to cooled, sterilized media.

Item-specific pharmacopeial certifications/lot performance criteria: Not specified for this item; refer to CoA/Spec Sheet.

Physical Properties

As a dehydrated culture medium, Potato Dextrose Agar (USP) presents as a blend of solids with properties determined by its composite ingredients.

Item-specific physical data:

• Appearance: Not specified for this item; refer to CoA/Spec Sheet.
• Density, MP/BP, refractive index, logP: Not applicable to a heterogeneous solid mixture; Not specified for this item; refer to CoA/Spec Sheet.

Literature/general properties (typical for PDA media; not item-specific):

• Form: Free‑flowing, tan to light beige, dehydrated powder that hydrates in water upon heating.
• Solubility: Dispersible in water; requires heating/boiling to fully dissolve agar. Insoluble in organic solvents.
• Gelation: Solidifies on cooling (approx. 40–45 °C) to a firm gel; melts at ~85–90 °C (agar gel, literature/general).
• Typical working concentration: Commercial PDA formulations commonly specify ~39 g/L to prepare agar plates (literature/general; consult label/CoA for this item’s specification).
• Typical reaction/medium pH: ~5.6 ± 0.2 at 25 °C after sterilization (USP/literature), favoring fungi/yeasts and suppressing many bacteria.

Practical notes (general):

• Dissolve by heating with frequent swirling to avoid localized scorching.
• For clear gels, avoid excessive boiling which can hydrolyze agar and darken the medium.
• Medium clarity and gel strength depend on water quality and precise concentration.

Always defer to the product label and CoA/SDS for any item‑specific physical parameters.

Quality and Grades

• Item grade: BioReagent (from Product Data). This denotes suitability for general laboratory/biological workflows, prepared to minimize contaminants that could interfere with microbiological cultivation, though exact contaminant limits are lot‑specific.
• Designation: Potato Dextrose Agar (USP). In practice, “USP” media are formulated to meet the United States Pharmacopeia requirements for composition/performance in microbiological quality tests (e.g., growth promotion for specified yeasts/molds). Verification of conformance should be based on the lot‑specific CoA and, where applicable, internal QC testing.

What the grades imply (general):

• BioReagent: Emphasis on consistency, low bioburden, and reliable performance in life‑science assays. Heavy‑metal content, UV cutoff, and other analytical solvent metrics are not relevant for this class.
• USP designation (general):
  • Composition and pH aligned with pharmacopeial description.
  • Performance criteria typically include robust growth of challenge organisms (e.g., Candida albicans, Aspergillus brasiliensis) within defined timeframes (literature/general). Specific strains/criteria must be confirmed per USP chapter and CoA.

Item‑specific notes:

• Exact formulation, pH range, fill weight, and performance metrics: Not specified for this item; refer to CoA/Spec Sheet.
• Stabilizers/preservatives: PDA is typically preservative‑free to allow broad microbial growth (literature/general). If any additives are present in this item, consult the label/CoA.

Reaction and Applications

This item is not a reagent for chemical synthesis; instead, it is a microbiological medium. Below are typical laboratory applications (literature/general):

• Cultivation and maintenance of yeasts and filamentous fungi: PDA’s acidic pH (~5.6) and rich carbohydrate content favor fungal growth and sporulation for morphological studies.
• Enumeration of yeasts and molds in food, beverage, environmental monitoring, and cosmetics using pour‑plate or spread‑plate methods.
• Microbiological QC: Growth promotion testing of compendial organisms per USP/EP/JP; suitability testing for microbial limits or environmental isolates (verify organism panel and acceptance criteria per chapter and CoA).
• Antifungal susceptibility screening (preliminary): PDA can be used for qualitative assessments or for growing inocula prior to standardized susceptibility tests (final testing often uses defined media; follow relevant standards).
• Sporulation/stock preparation: Promotes conidiation in many fungi, facilitating inoculum preparation for downstream assays.

Practical tips (general):

• Suppressing bacteria: Acidify molten PDA to pH ~3.5 with sterile 10% tartaric acid after autoclaving and cooling to ~50 °C (literature practice) to inhibit bacterial overgrowth when isolating fungi.
• Agar depth: Maintain 3–5 mm in plates for consistent colony size counts.
• Incubation: Typical ranges are 20–30 °C for 2–7 days depending on organism (literature/general). Record incubation conditions with each assay.

Always align with your lab’s SOPs and relevant pharmacopeial/ISO methods.

Reaction Conditions

For this material, “reaction conditions” correspond to media preparation and sterilization conditions (literature/general guidance; verify against your SOPs and the product label):

• Typical working concentration: Many commercial PDA products specify ~39 g per liter of water. Consult the label/CoA for the exact mass for this item.
• Dissolution: Suspend dehydrated PDA in cold water, then heat with frequent mixing to achieve complete solution. Avoid scorching.
• Sterilization: Autoclave at 121 °C for 15 minutes (15 psi). Do not over‑sterilize to prevent agar hydrolysis and nutrient degradation.
• Pouring plates: Cool molten medium to 45–50 °C before aseptic pouring. Typical plate fill: 18–25 mL for 90–100 mm plates, yielding ~3–4 mm depth.
• pH adjustment/selectivity: For enhanced suppression of bacteria, aseptically add sterile 10% tartaric acid to cooled, sterilized PDA to reach pH ~3.5 (literature practice). Mix gently to avoid bubbles.
• Incubation (general): 20–30 °C for 2–7 days depending on organism; monitor plates daily to avoid overgrowth when enumerating colonies.
• Expected outcomes: Robust growth of a broad spectrum of yeasts and molds; growth promotion of compendial strains should meet acceptance criteria defined by the relevant pharmacopeial chapter when the medium is prepared and stored correctly (verify via QC testing).

Water quality, sterilization accuracy, and aseptic technique critically influence performance.

Safety and Handling

Hazard classification for this specific catalog item is not provided here. Always review the lot‑specific SDS before use.

Item-specific hazard data:

• 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 (literature/best practice):

• PPE: Wear lab coat, safety glasses, and appropriate gloves. Use dust mask/respirator if dust generation is significant during weighing.
• Handling: Minimize dust. Avoid inhalation and contact with eyes/skin. Hot media can cause thermal burns; handle flasks and plates carefully after autoclaving/microwaving.
• Biohazard considerations: Though dehydrated PDA is non‑clinical, plates inoculated with environmental or test organisms become biohazardous. Dispose of spent media/plates by autoclaving or appropriate chemical disinfection per institutional biosafety procedures.
• Incompatibilities: Avoid strong oxidizers contacting the dry powder. Do not seal hot agar tightly—allow venting to prevent pressure buildup.
• First aid (general): If inhaled, move to fresh air. On skin/eye contact, rinse with water. If ingested or after exposure to hot media, seek medical attention as appropriate.

Storage conditions (from Product Data):

• Store at room temperature in a tightly closed container, protected from moisture and excessive heat. Ship: Normal.

Always consult the SDS for authoritative hazard and response information.

Solvent Selection

This product is a solid culture medium intended to be hydrated with water; it is not used as a solvent.

• Primary solvent: Purified/distilled water (literature/general). The ionic content and hardness of water can affect gel clarity and strength; use deionized water for reproducibility.
• Miscibility: Not applicable. Upon heating, agar dissolves in water; other common laboratory solvents are neither required nor suitable.
• When to choose PDA vs alternatives (general):
  • Choose PDA for robust growth and enumeration of yeasts and molds, especially from environmental, food, or cosmetic samples.
  • Consider Sabouraud Dextrose Agar (SDA) when a higher dextrose level and peptone-based nitrogen source are desired.
  • Use Malt Extract Agar (MEA) for certain filamentous fungi where maltose/malt extract enhances sporulation.

For solvent-like considerations relevant to preparation, see Reaction Conditions and Application Protocols.

Storage and Reconstitution

Item‑specific storage and shipping (from Product Data):

• Storage Conditions: Room temperature.
• Shipped In: Normal conditions.

General storage guidance (dehydrated medium):

• Keep container tightly closed, dry, and protected from humidity and direct sunlight. Use in a low‑moisture environment to prevent clumping and microbial contamination.
• Reseal promptly after opening. Record open date and lot number. Avoid cross‑contamination with scoops/spatulas.

Reconstitution/preparation (literature/general; confirm with label/CoA):

• Typical mass: Follow the manufacturer‑specified grams per liter (commonly ~39 g/L for PDA; do not assume—verify).
• Hydrate in purified/deionized water with heating until completely dissolved.
• Sterilize by autoclaving at 121 °C for 15 minutes. Allow to cool to 45–50 °C before pouring plates or dispensing.
• Optional selective modification: After sterilization and cooling, aseptically add sterile supplements (e.g., 10% tartaric acid for pH ~3.5) as required by your method.

Prepared media storage (general):

• Plates: Store inverted in sealed sleeves to limit desiccation; typical storage 2–8 °C for up to several weeks depending on SOP and performance checks.
• Broths/slants (if prepared): Store refrigerated and monitor for contamination or dehydration.

For research use only. Always consult the CoA/SDS and your laboratory SOPs for item‑specific directions and safety information.

Structure and Identity

Potato Dextrose Agar (USP) is a complex, multi‑component, dehydrated microbiological culture medium rather than a single, defined chemical substance. Consequently, discrete molecular identifiers (SMILES, InChIKey, single molecular formula) do not apply.

• Product type: Dehydrated culture medium composed typically of potato infusion/peptone derivatives, dextrose (glucose), and agar as a gelling agent (literature/general description).
• Functional composition (literature/general):
  • Potato infusion/nutrients: source of complex nitrogen, vitamins, and growth factors that support fungi and yeasts.
  • Dextrose (glucose): readily metabolizable carbon/energy source.
  • Agar: high‑gel‑strength polysaccharide matrix enabling colony formation and isolation.
• Structural features (descriptive): a heterogeneous mixture of polysaccharides (agar: agarose and agaropectin) and small molecules (glucose) with undefined average composition for the potato-derived fraction.

Item-specific identifiers:

• Molecular Formula: Not specified for this item; refer to CoA/Spec Sheet.
• Molecular Weight: Not specified for this item; refer to CoA/Spec Sheet.
• CAS, CID, InChIKey, SMILES: Not applicable for this complex medium; Not specified for this item; refer to CoA/Spec Sheet.

Note: The “USP” designation indicates conformance to the pharmacopeial description of Potato Dextrose Agar as a medium for the cultivation and growth promotion testing of yeasts and molds (literature/general). Verify current lot compliance via the CoA.

Synthetic Utility

Not applicable. Potato Dextrose Agar (USP) is a microbiological culture medium and is not used as a reagent or building block in chemical synthesis. For applications relevant to this product, see Reaction & Applications, Application Protocols, and Pharmaceutical Uses.

Target Specificity

This section is not applicable. Potato Dextrose Agar (USP) is not an antibody, probe, or affinity reagent and does not have target antigens, epitopes, or clone/isotype characteristics. For organism recovery and selectivity considerations, see Reaction & Applications and Application Protocols.