Ashby Medium - BioReagent

Cat. No.: A1528495

グレード＆純度 BioReagent

Storage

Room temperature

Shipped In

Normal

概要

For the cultivation of nitrogen-fixing bacteria

仕様

仕様と純度

BioReagent

保管条件

Room temperature

入荷

Normal

等級

BioReagent

Product Line

生物製品

Application Protocols

No manufacturer-validated protocols were provided for this SKU. The following are literature-based, non-item-specific examples for Ashby-type media.

Example A: Isolation of Azotobacter from soil (plates)

• Prepare Ashby agar as per formulation (Not specified for this item; follow label/CoA). Sterilize and pour plates.
• Perform 10-fold serial dilutions of soil suspension in sterile saline.
• Spread 100 µL of appropriate dilutions on Ashby plates.
• Incubate at 28–30 °C for 3–5 days. Look for large, mucoid colonies typical of Azotobacter.
• Purify by re-streaking; confirm nitrogen fixation by growth on N-free broth and ARA if required.

Example B: Enrichment in liquid culture

• Inoculate 50–100 mL Ashby broth with environmental sample.
• Incubate with vigorous shaking (e.g., 180–220 rpm) at suitable temperature.
• Subculture onto Ashby agar to isolate colonies.

Notes

• Maintain nitrogen-free conditions: Use nitrogen-free supplements and rigorously cleaned glassware.
• Include controls: Parallel plates with a small amount of combined nitrogen can serve as growth controls.

Always adapt parameters (agar concentration, incubation time/temperature) based on organism and follow the item’s CoA/Spec Sheet for any specific instructions.

Biological Roles

Ashby Medium plays an enabling role in microbiology by providing a nitrogen-free, mineral-balanced environment with a defined carbon source to select for and study free-living nitrogen-fixing bacteria.

Biological context (literature/general):

• Selection pressure: Absence of combined nitrogen forces reliance on atmospheric N2 fixation via nitrogenase. This favors growth of diazotrophs such as Azotobacter and Beijerinckia in environmental samples.
• Carbon and energy metabolism: Common Ashby variants offer mannitol or sucrose; diazotrophs oxidize these substrates to support ATP/reducing equivalent demands of nitrogenase.
• Mineral requirements: Balanced phosphate, Mg2+, Ca2+, Fe3+, and trace metals support enzyme cofactors and cell envelope synthesis. Excess fixed nitrogen (e.g., NH4+, NO3−) represses nif gene expression—hence omission from the formulation.
• Biofilm/exopolysaccharide: Some isolates produce copious exopolysaccharides on Ashby agar, aiding colony morphology-based identification.
• Ecological relevance: Facilitates recovery of free-living diazotrophs involved in soil nitrogen cycling and plant–microbe interactions.

Limitations:

• Not all diazotrophs thrive on the same carbon source; carbon-switch experiments may be needed.
• Trace contamination with nitrogen (e.g., from impure water or glassware residues) can reduce selectivity.

Note: This section summarizes biological function of Ashby-type media in general; it does not specify exact composition or performance of SKU A1528495.

Buffer Applications

Ashby Medium is a microbiological growth medium and is not typically used as a standalone laboratory buffer.

• While the salt system in Ashby-type media provides some intrinsic buffering capacity (often from phosphates; literature), the intent is selective cultivation under nitrogen-free conditions, not precise pH control for biochemical assays.
• For dedicated buffering needs (enzyme assays, electrophoresis), use appropriate defined buffers (e.g., phosphate, HEPES, MOPS) prepared independently of growth media.

Item-specific buffer capacity, composition, or recommended pH ranges are Not specified for this item; refer to CoA/Spec Sheet.

Green Alternatives

Sustainability considerations for microbiological media center on component sourcing, waste minimization, and laboratory energy use rather than replacement with “greener” solvents or reagents.

• Component sourcing: Ashby Medium (literature) uses simple mineral salts and a carbohydrate (e.g., mannitol or sucrose). Preference for sustainably produced carbon sources (e.g., certified sucrose) can reduce upstream footprint. Item-specific sourcing is Not specified for this item; refer to CoA/Spec Sheet if available.
• Energy: Autoclaving is energy-intensive. Batch preparation and efficient autoclave loading reduce energy per liter. Consider validated lower-cycle sterilization only where allowed by QA policies.
• Waste: Nitrogen-free media often produce lower biomass than rich media, potentially reducing biohazardous waste volumes for screening workflows. Use concentrated stock solutions to reduce packaging.

Comparison of nitrogen-free media (literature/general):

• Ashby (mannitol-based): Simple, readily biodegradable carbon source; well-established for Azotobacter.
• Burk’s medium: Similar goal with different phosphate/trace composition; may offer improved buffering capacity.
• Jensen’s medium: Often sucrose-based; can be economical and plant-derived.

Trade-offs:

• Different media adjust phosphate and trace-metal loads, influencing eutrophication potential in liquid waste. Neutralize/retain wastes per local regulations prior to disposal.

No greener chemical substitute is typically sought; rather, optimize preparation scale, sterilization efficiency, and waste handling.

Pharmaceutical Uses

This product is intended for research use only (per Product Data) and is not manufactured for pharmaceutical formulation or clinical diagnostic use.

General context (literature/general):

• Microbiological media like Ashby Medium may be used in R&D settings for environmental isolate characterization or microbial process development studies, but they are not pharmacopeial excipients nor production media for regulated manufacturing unless specifically qualified.

Item-specific pharmacopeial status, excipient role, or GMP suitability are Not specified for this item; refer to CoA/Spec Sheet and your quality unit if considering use beyond basic research.

Physical Properties

• Appearance: Not specified for this item; refer to CoA/Spec Sheet.
• Grade/Purity: BioReagent (see Quality & Grades).
• Storage conditions: Room temperature (per Product Data).
• Shipping: Normal (per Product Data).

General physical characteristics (literature/general for Ashby-type media):

• Supplied either as a dry, free-flowing powder blend or as a ready-to-use solution; this listing does not specify the form.
• Typical working solution pH is near neutral (often pH 7.0 ± 0.2 before sterilization), but exact pH for this item is Not specified; refer to CoA/Spec Sheet.
• Solubility: Components are water-soluble; reconstitution is in purified/deionized water.
• Osmolality and conductivity depend on the exact salt composition and preparation concentration (literature: modest ionic strength compared to rich complex media).

Do not treat any of the above as specifications for SKU A1528495 unless explicitly stated. For exact concentration, pH target, appearance, and any QC limits, consult the product CoA/Spec Sheet.

Quality and Grades

• Item grade: BioReagent (per Product Data).

What BioReagent typically implies (general):

• Suitable for research and laboratory applications requiring consistent formulation and low levels of typical contaminants that could interfere with microbial growth or biochemical assays.
• Manufactured and QC’d to specifications appropriate for laboratory research (not clinical diagnostics, GMP manufacturing, or therapeutic use). Batch-to-batch consistency, solubility, and pH on preparation are commonly monitored.

Item-specific notes:

• Exact quality attributes (component assay ranges, bioburden/endotoxin, particulate profile, pH target upon reconstitution, and any sterility testing) are Not specified for this item; refer to CoA/Spec Sheet.
• Stabilizers or anti-caking agents, if any, are Not specified for this item; refer to CoA/Spec Sheet.

Practical implications:

• For reproducible microbial selection/enrichment (e.g., of diazotrophs), verify the lot’s performance parameters listed on the CoA (pH after reconstitution, clarity, growth performance with control strains) and document lot numbers for continuity in biological studies.

Reaction and Applications

This product is a microbiological growth medium used in life science research, not a reagent for synthetic organic reactions.

Research applications (literature/general for Ashby-type media):

• Enrichment and isolation of free-living diazotrophs (e.g., Azotobacter spp., Beijerinckia spp.) by providing carbon and minerals but no fixed nitrogen, thereby selecting organisms capable of N2 fixation.
• Colony morphology studies on Ashby agar enable visual discrimination of mucoid, pigmented, or slimy colonies typical of Azotobacter.
• Nitrogen fixation studies: Pre-growth of cultures for acetylene reduction assay (ARA) or 15N2 incorporation experiments.
• Ecological microbiology: Enumeration and recovery of diazotrophs from soil/rhizosphere samples via serial dilution and plating on nitrogen-free medium.
• Physiology and regulation: Assessing the impact of carbon source, phosphate level, or trace metals on nif gene expression and growth under nitrogen limitation.

Practical tips (general guidance):

• Maintain strict nitrogen-free conditions: Avoid contamination from ammonium salts, nitrates, amino acids, or peptones in glassware and supplements.
• Carbon source choice matters: Mannitol or sucrose are commonly used in Ashby variants; different isolates may prefer one over the other.
• Aeration: Many diazotrophs are obligate aerobes with high oxygen demand; ensure adequate shaking for broth cultures or proper plate incubation.
• Controls: Include a nitrogen-supplemented control plate/broth to assess selectivity and culture viability.

Note: Manufacturer Applications were not provided for this SKU; the above are literature-based examples, not item-specific performance claims.

Reaction Conditions

Chemical reaction conditions are not applicable to this product. However, preparation and cultivation conditions are central to its intended use (literature/general guidance):

• Reconstitution: Dissolve the specified mass of medium in purified water to the target volume (exact mass per liter for SKU A1528495 is Not specified; refer to CoA/Spec Sheet). Mix until fully dissolved.
• pH: Adjust to the formulation’s target pH (commonly near neutral, ~7.0; literature) before sterilization unless otherwise directed by the manufacturer.
• Sterilization: Autoclave at 121 °C for 15–20 minutes (typical). For heat-labile supplements (if any), sterile-filter and add aseptically after cooling to ~50–55 °C.
• Agar plates: If preparing solid medium, dissolve agar according to the formulation (concentrations vary; Not specified for this item). Pour plates under aseptic conditions.
• Incubation: Grow cultures at organism-appropriate temperature and aeration (e.g., 28–30 °C for many soil diazotrophs; literature). Shaking speeds of 150–250 rpm are commonly used for broth cultures to meet O2 demand.

These are general literature practices for Ashby-type media and are not item-specific directions. Always follow the label and CoA/Spec Sheet for SKU A1528495.

Safety and Handling

GHS/Regulatory status for this specific item:

• Signal word: Not specified for this item; refer to SDS.
• Hazard statements (H-phrases): Not specified for this item; refer to SDS.
• GHS classification and pictograms: Not specified for this item; refer to SDS.

General safety guidance (microbiological media; literature/best practice):

• PPE: Wear lab coat, safety glasses, and appropriate gloves when handling dry powder or solutions. Avoid inhalation of dust and contact with eyes/skin.
• Hygroscopicity/dusting: Medium powders can generate nuisance dust; handle in a clean area or fume hood to minimize inhalation and cross-contamination.
• Incompatibilities: Avoid contact with strong acids/bases that could depolymerize/precipitate components or alter pH drastically; avoid oxidizers with carbohydrate-containing media.
• Sterilization: Many users autoclave reconstituted media (e.g., 121 °C for 15–20 min; literature). Allow to cool before pouring plates. Do not seal containers tightly during autoclaving. Some heat-labile supplements (if used) should be filter-sterilized separately and added aseptically post-autoclave.
• Microbiological caution: Use aseptic technique to prevent unintended cultivation of environmental organisms. Decontaminate spills with appropriate disinfectant (e.g., 10% bleach) and dispose of biological waste per institutional biosafety procedures.
• First aid (overview): If inhaled, move to fresh air; if in eyes/skin, rinse with water; if ingested, rinse mouth. Seek medical attention as needed. Always defer to the SDS for authoritative guidance.

Solvent Selection

Ashby Medium is prepared in purified water; organic solvents are not applicable.

• Primary solvent: Water (Type 1/2 DI or equivalent). Use freshly produced, low-conductivity water to minimize variability due to adventitious nitrogen or trace metals.
• Miscibility: Fully water-soluble at the specified preparation concentration (exact concentration for this item is Not specified; refer to CoA/Spec Sheet).
• pH control: Adjust with sterile 1 N HCl/NaOH if the formulation requires a specific pH prior to sterilization (literature often targets ~pH 7.0). Avoid buffering with nitrogen-containing buffers (e.g., Tris, ammonium-based) if maintaining nitrogen-free selection is essential.
• Sterilization method: Autoclave the reconstituted medium, or filter-sterilize if heat-sensitive supplements are included (supplements added aseptically post-sterilization). Use borosilicate glass or autoclavable polymerware.

Comparison (literature/general):

• Ashby vs. rich media (LB, TSA): Ashby is chemically defined and nitrogen-free, selecting for N2-fixing bacteria; rich media supply organic nitrogen and undermine selection.
• Ashby vs. other N-free media (Jensen’s, Burk’s): All are nitrogen-free, but differ in carbon source, phosphate balance, and trace elements. Choice affects growth rates and colony morphology. Ashby with mannitol commonly supports Azotobacter isolation.

Storage and Reconstitution

• Storage conditions (as supplied): Room temperature (per Product Data). Protect from moisture and microbial contamination. Keep container tightly closed.
• Shipping: Normal (per Product Data).
• Shelf life/expiry: Not specified for this item; refer to CoA/Spec Sheet and product label.

Reconstitution and use (literature/general for Ashby-type media; not item-specific):

• Preparation: Dissolve the specified mass of medium in purified water to the target volume indicated on the label/CoA. Mix until fully dissolved. Adjust pH as directed by the formulation (often near pH 7.0 before sterilization).
• Sterilization: Autoclave at 121 °C for 15–20 minutes. If preparing agar plates, maintain molten medium at ~50–55 °C before pouring.
• Supplements: If adding heat-labile trace elements or vitamins, sterile-filter and add aseptically after autoclaving and cooling.
• Storage of prepared medium: Store sealed plates at 2–8 °C and use within 1–2 weeks for best performance (general practice). Store sterile broth at 2–8 °C and use promptly; avoid repeated warming/cooling that can cause precipitation.

All item-specific preparation masses, target pH, and stability limits are Not specified for this item; refer to the product CoA/Spec Sheet. For research use only.

Structure and Identity

Ashby Medium is a defined microbiological growth medium, not a single chemical compound. It is typically formulated as a nitrogen-free mineral salts medium with a single carbon source to select for free-living diazotrophs.

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

Structural/Compositional overview (literature):

• Classic Ashby medium is a nitrogen-free selection medium featuring a carbon source (often mannitol), inorganic salts (e.g., phosphates, Mg2+, Ca2+, Fe3+), and no fixed nitrogen to favor growth of N2-fixing bacteria.
• The 2D “structure” is best understood as a blend of ionic salts and an organic carbon source; no stereochemical descriptors apply.

Notes

• Different variants exist (e.g., mannitol-, sucrose-, or glycerol-based Ashby formulations; with/without trace elements). This listing does not specify the exact component list or concentrations; consult the product CoA/Spec Sheet for the authoritative composition of SKU A1528495.

Synthetic Utility

Not applicable. Ashby Medium is a formulated growth medium for microbiological cultivation, not a synthetic organic reagent or building block. It does not participate as a defined reactant, catalyst, or solvent in chemical synthesis.

For applications relevant to this product, see Reaction & Applications and Biological Roles.

Target Specificity

This product is not an antibody, probe, or targeted biochemical. It is a growth medium designed to select for organisms capable of nitrogen fixation by withholding combined nitrogen sources.

• Item-specific target data (antigen, epitope, species reactivity, clone, isotype) are not applicable.