AK Agar No. 2 - BioReagent

Cat. No.: A1528588

GRADE & PURITY BioReagent

Storage

Room temperature

Shipped In

Normal

Vue d’ensemble

For preparation of spore suspension when testing antibiotic residues in milk and dairy products

Specifications

Spécifications et pureté

BioReagent

Conditions de stockage de stockage

Room temperature

Expédié en

Normal

Grade

BioReagent

Product Line

Produits biologiques

Application Protocols

The following general laboratory protocols illustrate common uses of agar. They should be adapted to your media formulation and organism requirements.

A. Preparing 1 L of LB agar plates (general example):

1. Dissolve LB powder (as per manufacturer) in ~900 mL DI water. Add 15 g agar (1.5% w/v). Bring volume to 1 L.
2. Heat to dissolve and autoclave at 121 °C for 15 min.
3. Cool to 50–55 °C; add sterile antibiotic as needed (e.g., ampicillin to 100 µg/mL). Swirl gently.
4. Pour ~20–25 mL per 90 mm sterile Petri dish. Allow to set. Dry surface if necessary.
5. Store inverted at 2–8 °C in sealed sleeves/bags.

B. Soft agar overlay for phage/plaque assays (general):

1. Prepare bottom plates with 1.5% agar in the chosen medium.
2. Prepare soft agar at 0.6–0.7% agar; keep molten at 45–50 °C.
3. Mix host cells, phage, and soft agar; pour onto bottom plates and allow to set before incubation.

C. Motility test (soft agar, general):

1. Prepare medium with 0.3–0.5% agar in tubes or plates.
2. Inoculate with a straight stab; incubate under appropriate conditions; assess turbidity spread.

D. Plant tissue culture medium (general):

1. Prepare MS or other basal salts with vitamins; adjust pH (e.g., 5.7–5.8).
2. Add 6–10 g/L agar; autoclave. Pour plates or dispense into culture vessels.

Note: Manufacturer‑specific protocols are not provided in the Product Data. Validate and QC plate sterility and firmness before experimental use.

Biological Roles

Agar functions as an inert structural matrix in laboratory biology rather than as a metabolite. Its utility derives from its general resistance to microbial degradation and its benign interaction profile with most organisms.

• Origin (literature): Extracted from red algae (e.g., Gelidium, Gracilaria). In algae, the agarans (including agarose/agaropectin) contribute to cell wall architecture and mechanical strength.
• Metabolism by microbes (literature): Most bacteria and yeasts cannot utilize agar as a carbon source, enabling it to serve as a non‑nutritive solidifying agent. A subset of marine or soil microbes produce agarases and can liquefy agar; this is uncommon in standard clinical or lab strains.
• Interaction with cells: Generally inert toward microbial growth besides physical support. Charged groups in agaropectin can weakly affect diffusion or interaction of some dyes or proteins; agarose minimizes such effects.
• Diffusion properties: Hydrogels formed at 1–2% w/v have pore sizes that permit diffusion of small molecules, antibiotics, and many secreted factors while restricting convection—useful for gradient formation and colony isolation.
• Plant tissue culture: Provides mechanical support for explants and regulates water availability; low impurity agars reduce phenolic interactions and tissue browning (general observation).

Note: No therapeutic or clinical claims are made. For organism‑specific interactions or sensitivity to agar impurities, consult organism‑focused literature and validate empirically with your strain and media formulation.

Buffer Applications

Agar is not a buffering agent and does not itself establish pH. However, it is routinely used as the solidifying matrix for buffered media and assay gels.

• Use with buffers (general): Prepare agar in the desired buffer or culture medium (e.g., PBS, Tris, HEPES, LB/NB) and adjust pH prior to sterilization. The buffer controls pH; agar provides structure.
• Diffusion assays: Buffered agar plates are employed for antibiotic susceptibility (disc diffusion), enzyme diffusion, and chemotaxis assays where stable pH and ionic strength are essential.
• Soft agar overlays: Prepared in the same buffer or medium as the base plate to maintain consistent pH/osmolarity, typically at 0.6–0.8% w/v agar.
• Electrophoresis: For nucleic acid electrophoresis, agarose—not agar—is the standard matrix due to reduced charged impurities; use TAE/TBE buffers with agarose.

Practical notes:

• Adjust pH of the medium before adding heat‑labile components. Avoid strong acid/alkali during sterilization to limit hydrolysis and loss of gel strength.
• For organisms sensitive to inhibitory anions, choose low‑sulfate agar or validate the chosen agar grade with your buffer/medium composition.

Item-specific buffer capacity, pKa, or ionic contributions: Not applicable to agar; Not specified for this item; refer to CoA/Spec Sheet.

Green Alternatives

Agar itself is a renewable, biodegradable biopolymer sourced from marine red algae, with an excellent safety and environmental profile in laboratory use. Nonetheless, alternative gelling agents may offer advantages for specific sustainability or performance goals.

Comparison (literature/general):

• Agar
  • Source: Red algae (renewable)
  • Pros: Broad microbial compatibility; sets at ~32–40 °C; melts at ~85–95 °C; widely available; biodegradable.
  • Cons: Natural variability; charged agaropectin fraction may influence certain assays; requires heating to dissolve.
• Agarose
  • Source: Purified fraction of agar
  • Pros: Lower sulfate/impurity content; superior optical clarity; minimal interaction with biomolecules.
  • Cons: Higher cost; similar energy input to dissolve.
• Gellan gum
  • Source: Microbial fermentation (Sphingomonas)
  • Pros: Strong, transparent gels at lower concentrations; precise, fermentation‑based supply; tunable with cations.
  • Cons: Gelation often requires specific ions; different mouthfeel/texture in food analogs (less relevant to lab).
• Carrageenan (κ/ι)
  • Source: Red algae
  • Pros: Forms strong gels with K+/Ca2+; can be very transparent.
  • Cons: Ion‑dependent; interactions with proteins may be stronger than agar.

Sustainability notes:

• Energy use is dominated by heating/sterilization. Lowering batch sizes, using pressure cookers/autoclaves efficiently, and minimizing over‑sterilization reduce energy footprint.
• Reusable glassware for pouring plates reduces plastic waste. Where appropriate, consider pour‑on‑demand systems instead of pre‑poured disposables.

Pharmaceutical Uses

This product is designated For research use only and is not intended for human or veterinary use. The following notes describe general, non‑clinical roles of agar in pharmaceutical research and manufacturing contexts (literature/general):

• Microbiological quality control: Solid media for bioburden testing, microbial limit tests, and environmental monitoring in facilities (e.g., nutrient agar, TSA). Agar’s consistent gelation and low nutrient contribution make it ideal for plate media.
• Process development: As a gelling agent in prototype formulations during early R&D studies (e.g., topical gel prototypes, mucoadhesive platforms) before translation to GMP‑grade materials; final products typically require pharmacopeial grades and validation.
• Analytical assays: Diffusion‑based potency assays for antibiotics or antiseptics on agar plates.
• Cell culture adjunct: Support matrix in plant/yeast selection plates used in strain engineering and genetic screening relevant to bioprocess development.

Notes and limitations:

• No claims of therapeutic efficacy, safety, or final dosage‑form suitability are made for this item.
• For GMP or compendial applications (e.g., USP/NF agar, EP), select pharmacopeia‑compliant grades and document gel strength, ash, sulfate, and microbial limits accordingly.
• Additives and actives determine regulatory classification; validate media performance with your organism panel before QC use.

Physical Properties

Item-specific numeric specifications are not provided in the Product Data. The following are typical literature characteristics for agar as a class of materials; do not construe as the specification for this item.

• Appearance: Not specified for this item; refer to CoA/Spec Sheet. (Typically an off‑white to beige powder or flakes; literature)
• Solubility (literature):
  • Insoluble in cold water; swells to form a suspension.
  • Soluble in hot/boiling water (~95–100 °C), forming clear to slightly opalescent solutions at 0.5–2.5% w/v, depending on grade.
  • Generally insoluble in organic solvents; dispersible in some polyols when heated with water present.
• Gelation/melting (literature):
  • Gelation (gelling) temperature commonly ~32–40 °C for many agars at standard ionic strength.
  • Melting temperature commonly ~85–95 °C; thermal hysteresis between gelation and melting is characteristic.
• pH behavior (literature): Stable gels typically in pH ~5–8; hydrolysis accelerates under strong acid/alkali at elevated temperature.
• Density/bulk density: Not specified for this item; refer to CoA/Spec Sheet.
• Ash, moisture, sulfate, gel strength: Not specified for this item; refer to CoA/Spec Sheet.
• Optical properties: Not specified for this item; refer to CoA/Spec Sheet. (Agar solutions are generally low‑UV absorbing but may exhibit background at <230 nm; literature)

Practical notes (general): Ionic strength, sugars, and divalent cations can modulate gel point and gel firmness. Overheating in strong acid or prolonged autoclaving can reduce gel strength via hydrolysis.

Quality and Grades

• Grade/Purity (from Product Data): BioReagent.

What BioReagent grade generally implies (general guidance):

• Sourced and controlled for laboratory and biochemical use, with attention to impurities that could interfere with microbial growth, enzymatic reactions, or cell‑based work.
• Often includes controls on parameters such as gel strength, clarity, ash, sulfate, and microbial bioburden/endotoxin—however, exact acceptance criteria are product‑ and lot‑specific.

This item-specific guidance:

• Numeric specifications (e.g., gel strength, moisture, ash, sulfate, clarity) are Not specified for this item; refer to CoA/Spec Sheet.
• Stabilizers/preservatives: Not specified for this item; refer to CoA/Spec Sheet. (Most agars are provided neat without added stabilizers.)
• Intended use: For research use only (from Product Data). Not for human or veterinary use.

Selecting a grade for your workflow (general):

• Microbiology plating and routine culture: Standard agar grades are typically sufficient if they exhibit reliable gelation at 1.2–2.0% w/v and low inhibitory impurities.
• Sensitive microbial assays (e.g., antibiotic susceptibility, bacteriophage, chemotaxis): Choose agar with low inhibitory contaminants and clear gels; sometimes specialized low‑sulfate or water‑washed agars are preferred.
• Molecular biology/electrophoresis: Use agarose rather than agar for nucleic acid separations to minimize charged/branched components.

Documentation:

• For lot‑specific COA values and test methods aligned to this BioReagent grade, request the CoA/Spec Sheet with your shipment or from customer support.

Reaction and Applications

Agar is not used as a reagent in chemical synthesis; its value is as an inert, thermo‑reversible hydrogel matrix across microbiology and analytical workflows.

Core laboratory applications (general):

• Microbial culture media: Solidifying agent for nutrient, selective, and differential agars (e.g., LB agar, MacConkey, PDA). Typical working concentrations 1.2–2.0% w/v; soft agar 0.3–0.7% for motility/phage assays; overlays 0.6–0.8%.
• Plant and algal tissue culture: Gelling medium for aseptic growth and selection.
• Diffusion and bioassays: Antibiotic susceptibility (disc diffusion), chemotaxis, and enzyme diffusion tests where controlled porosity is required.
• Environmental and food microbiology: Enumeration plates and selective isolation media.

Practical considerations:

• Sterilization: Autoclave at 121 °C for ~15 min for typical volumes; excessive sterilization times degrade gel strength.
• Thermal handling: Cool to ~50–55 °C before adding heat‑labile supplements (antibiotics, dyes) and pouring plates; avoid condensation by equilibrating plates at room temperature before use.
• Media performance: Impurities (e.g., sulfate, phenolics) in lower grades can inhibit fastidious organisms; BioReagent‑grade products are selected to minimize such effects.
• Modulating gel properties: Increase % w/v to raise firmness; ionic strength and divalent cations generally increase gel strength and can slightly raise gelation temperature.

Analytical/engineering uses (general):

• Immobilization matrix for whole cells or enzymes in teaching labs.
• Model porous medium for diffusion, transport, and colony morphology studies.

Note: Manufacturer Applications field is empty in the Product Data; the above reflects common literature uses of agar.

Reaction Conditions

For agar, “reaction conditions” translate to reliable dissolution, sterilization, and gelation protocols. The following are general literature practices; optimize for your media and lab setup.

Standard agar plate preparation (general):

• Concentration: 1.2–2.0% w/v for firm plates; 0.6–0.8% for overlays; 0.3–0.5% for motility/soft agar.
• Dissolution: Suspend agar powder in cold medium or water with stirring (e.g., 15 g/L for 1.5%). Heat to boiling until fully dissolved. Alternatively, autoclave at 121 °C for ~15 min (liquefaction completes during the cycle).
• Sterilization: Autoclave at 121 °C, 15 psi, 15–20 min for typical 250–1000 mL volumes. Avoid over‑sterilization to prevent hydrolysis and loss of gel strength.
• Additives: Cool to ~50–55 °C before adding heat‑labile components (antibiotics, indicators). Mix gently to avoid bubbles.
• Pouring: Pour 20–25 mL per 90 mm plate. Allow to solidify at room temperature; dry plates (lids ajar) if excess condensation forms.
• Storage of plates: Invert, bag, and store at 2–8 °C to limit dehydration/contamination; equilibrate to room temperature before use to avoid condensation. Shelf life depends on formulation (commonly 2–4 weeks; check your lab’s QC policy).

Other formats:

• Slants: 1.5–2.0% agar in screw‑cap tubes, sterilized and cooled at an angle.
• Stabs: 0.7–1.0% agar for motility or maintenance.

Quality checks:

• Visual clarity, absence of precipitate, correct gel firmness, and negative control sterility (incubate a plate uninoculated to check for contamination).

Item-specific conditions: Not specified for this item; refer to CoA/Spec Sheet.

Safety and Handling

GHS classification, signal word, and pictograms are not provided in the Product Data. Always consult the SDS for authoritative safety information.

• General hazard profile (literature/general): Agar is typically regarded as a low‑hazard laboratory reagent. The main risks are dust inhalation and mechanical irritation to eyes/respiratory tract. Heated agar solutions (near boiling) pose burn and scald hazards.
• Potential hazards:
  • Dust: May cause transient irritation; minimize airborne dust formation.
  • Hot liquids/steam: Severe burn risk during dissolution, autoclaving, and pouring plates.
  • Slip hazard if spilled gels form on floors.
• Recommended PPE: Laboratory coat, safety glasses or face shield when pouring, heat‑resistant gloves for hot vessels, and dust mask/respirator as appropriate during weighing in poorly ventilated areas.
• Handling practices:
  • Add powder gradually to vigorously stirred cold or room‑temperature water to minimize clumping; heat after wetting.
  • Do not tightly cap flasks during heating until boiling has subsided to prevent pressure buildup and bumping.
  • When using a microwave, use large headspace and intermittent swirling; beware of superheating.
• Incompatibilities (general): Strong acids or bases at elevated temperature (hydrolysis and depolymerization). Oxidizing agents may degrade polysaccharides. Avoid desiccant dust contamination.
• First aid overview (general, not a substitute for SDS):
  • Inhalation: Move to fresh air; seek medical advice if symptoms persist.
  • Eye contact: Rinse cautiously with water for several minutes; remove contact lenses; seek medical attention if irritation persists.
  • Skin contact: Wash with soap and water; for thermal burns from hot agar, cool with water and seek medical care.
• Waste: Agar solutions/gels without hazardous additives can typically be disposed of as nonhazardous aqueous waste or solid waste per institutional policy; additives determine final waste classification.

Solvent Selection

As a gelling polysaccharide, agar is processed in aqueous systems rather than organic solvent systems.

• Primary solvent: Water (deionized or distilled). Agar is insoluble in cold water but dissolves upon heating near boiling.
• Buffer compatibility (general): Common biological buffers (e.g., PBS, Tris, HEPES) and complex media (LB, nutrient broth) are compatible. Ionic strength and cations (e.g., Mg2+, Ca2+) can modulate gelation temperature and firmness.
• Additives: Sugars, peptones, and salts may alter viscosity and gel clarity. Antibiotics and indicators (e.g., X‑gal) can be added post‑sterilization when cooled to ~50–55 °C to avoid thermal degradation.
• pH considerations: Maintain media pH in a biologically relevant range (typically ~6–8 for many microbes) before sterilization; extreme pH plus heat can hydrolyze agar and reduce gel strength.
• Alternative solvent systems: Not typically applicable; agar does not dissolve in most organic solvents.

When to choose agar vs alternatives (general comparison):

• Agar: Robust, thermo‑reversible gel; wide microbial compatibility; minimal nutrient value to most microbes; gels at ~32–40 °C—ideal for plating.
• Agarose: Higher purity/neutrality; better for electrophoresis and sensitive diffusion assays; generally more expensive.
• Gellan gum: Forms strong, transparent gels; can set at lower concentrations; cation‑dependent gelation can be advantageous for some applications.

Practical tips:

• Wet out the powder in cold water with vigorous stirring before heating to minimize lumps.
• Use large vessels and boiling chips or intermittent venting to prevent boil‑over.
• Filter clarity improvements can sometimes be achieved by slow cooling without agitation.

Storage and Reconstitution

From Product Data:

• Storage conditions (as supplied): Room temperature.
• Shipped in: Normal.

General storage guidance (dry powder):

• Keep container tightly closed in a cool, dry place. Protect from moisture and odors (agar can adsorb volatiles). Avoid prolonged exposure to high humidity to prevent clumping and microbial contamination.
• Shelf life is lot‑dependent; consult the CoA/Spec Sheet for retest/expiry information.

Reconstitution/preparation (general):

• Concentration ranges: 0.3–2.0% w/v depending on application (soft agar to firm plates). Weigh accurately.
• Dissolution: Disperse in cold medium/water with stirring, then heat to boiling until fully dissolved. Alternatively, autoclave at 121 °C for ~15 min to sterilize and complete dissolution.
• Post‑sterilization handling: Cool to ~50–55 °C before adding heat‑sensitive supplements (antibiotics, indicators, nutrients) and pouring.
• Avoid repeated heat‑cool cycles; prolonged heating and multiple autoclave cycles can degrade gel strength.

Storage of prepared media (general):

• Plates: Store inverted in sealed sleeves/bags at 2–8 °C to minimize dehydration; typical in‑lab usability 2–4 weeks depending on formulation and sterility controls.
• Bottled molten agar: Can be maintained at 45–55 °C in a water bath for short periods (hours). For longer storage, allow to solidify and re‑melt once as needed; minimize repeated remelting.

Item-specific stabilizers, moisture limits, and gel strength: Not specified for this item; refer to CoA/Spec Sheet.

Research use note: For research use only (from Product Data).

Structure and Identity

AK Agar No. 2 is a complex, natural polysaccharide used as a high‑performance gelling agent for microbiology and life‑science applications. It is primarily composed of agarose (a neutral, linear galactan) and agaropectin (a sulfated/charged fraction) derived from red algae (Rhodophyceae).

• SKU: A1528588
• Product name: AK Agar No. 2
• Chemical class: Complex polysaccharide (galactan) mixture from marine algae; not a single defined small molecule
• Molecular formula: Not specified for this item; refer to CoA/Spec Sheet.
• Molecular weight: Not specified for this item; refer to CoA/Spec Sheet. (Note: agar is polydisperse; agarose repeating unit is (→3)-β-D-galactopyranose-(1→4)-3,6-anhydro-α-L-galactopyranose←)
• CAS, CID, InChIKey, SMILES: Not applicable to a mixture; Not specified for this item; refer to CoA/Spec Sheet.
• Structural features (literature):
  • Alternating D-galactose and 3,6‑anhydro‑L‑galactose residues linked β(1→4)/α(1→3) (agarose fraction).
  • Minor sulfate, pyruvate, and methoxyl substituents primarily in the agaropectin fraction.
  • No defined stereocenters at the overall product level beyond saccharide monomer configuration.
• 2D description in words (literature): Linear carbohydrate chains forming double helix aggregates upon cooling in water, yielding a thermo‑reversible hydrogel network with high water content and low protein/carbohydrate reactivity.

Notes:

• This item lacks small‑molecule identifiers by design due to its natural, polydisperse composition.
• For lot‑specific identity tests (e.g., gel strength, sulfate content, moisture, ash), consult the CoA.

Synthetic Utility

Agar is not a reactive chemical building block and is not typically used in small‑molecule synthesis. Its utility to synthetic chemistry and chemical engineering is as an inert, porous, aqueous gel matrix.

General uses in chemical workflows (literature):

• Immobilization/support: Entrapment of whole cells, enzymes, or catalysts in agar beads or slabs for teaching labs and low‑temperature biotransformations.
• Diffusion studies: Model matrix to quantify diffusion coefficients of reagents, dyes, or nanoparticles in water‑rich environments.
• Microfabrication/soft lithography (educational): Casting channels or simple molds; agar’s thermal reversibility allows rapid prototyping.
• Reaction quenching/separation: Physical separation of phases in teaching demonstrations; not a substitute for chromatographic media.

Why choose agar as a matrix:

• Aqueous, benign environment with minimal chemical reactivity toward common functional groups at neutral pH.
• Thermo‑reversible setting allows easy loading and recovery of entrapped species by warming.

Caveats:

• Not suitable for strongly acidic/basic or high‑temperature reactions due to hydrolysis and melting.
• Organic solvent resistance is poor; gels dehydrate/shrink or collapse in many organic media.

Item-specific reactivity or functionalization data: Not specified for this item; refer to CoA/Spec Sheet.

Target Specificity

Not applicable. AK Agar No. 2 is not an antibody, probe, or affinity reagent and has no target specificity parameters (e.g., antigen, clone, isotype). No item‑specific targeting data are provided.