Casein Agar (G.A) - BioReagent

Cat. No.: C1528457

GRADE & PURITY BioReagent

Storage

Room temperature

Shipped In

Normal

Overview

For viable bacteria testing of veterinary biological products. Preparation method: Weigh 42.01 g of this product in 1 L of distilled or deionized water (the volume may be scaled up or down proportionally), heat with stirring and boil until completely dissolved, dispense and autoclave at 116°C for 30 minutes. After sterilization, shake well to prevent agar from settling and solidifying at the bottom of the vessel, then set aside for use.

Specifications

Specifications & Purity

BioReagent

Storage

Room temperature

Shipped In

Normal

Grade

BioReagent

Product Line

Biological Products

Application Protocols

General protocol for preparing and using Casein Agar plates (literature guidance; adapt per your SOP and CoA/Spec Sheet):

Plate preparation:

• Weigh the required quantity of dehydrated medium (per CoA) and suspend in the corresponding volume of purified water.
• Heat with stirring until fully dissolved; avoid boiling over.
• Autoclave at 121 °C for ~15 minutes. Mix gently after sterilization to redistribute components.
• Cool to 45–50 °C. If needed, add sterile heat-labile supplements aseptically.
• Pour 20–25 mL per 90 mm plate in a laminar flow hood. Allow to solidify and dry surface moisture.

Assay for proteolysis (example workflow):

• Streak or spot-inoculate test organisms and proteolytic positive control strains.
• Incubate inverted plates at the organism-appropriate temperature until growth appears (typically 24–48 h for many mesophiles).
• Examine for clear halos around colonies indicating casein hydrolysis. For enhanced contrast, some protocols overlay with dilute acid or precipitating reagents to opacify unhydrolyzed casein (follow institutional SOPs).

Quality controls:

• Include uninoculated sterility controls.
• Record lot number, preparation parameters, and incubation conditions for reproducibility.

Note: Exact concentrations, pH targets, and performance specifications are Not specified for this item; refer to CoA/Spec Sheet.

Biological Roles

Biological context (general, literature):

• Casein: A family of milk phosphoproteins rich in proline, serving as a balanced nitrogen and amino acid source. Microbial extracellular proteases (e.g., serine proteases, metalloproteases) hydrolyze casein into peptides and amino acids that can be transported and metabolized.
• Agar: A largely inert gelling polysaccharide from red algae. It is generally not metabolized by most bacteria, providing a stable, non-nutritive matrix; a minority of marine bacteria possess agarases.

Microbial physiology insights:

• Protease production is often regulated by quorum sensing, nutrient limitation, or environmental signals; casein-containing media can induce expression of proteolytic systems in some taxa.
• Hydrolysis zones reflect diffusion of enzymes from colonies into the gel; halo size depends on enzyme activity, diffusion, substrate concentration, and incubation conditions.

Research uses:

• Screening environmental isolates for industrially relevant proteases (e.g., for detergent, food processing, or biocatalysis research) without implying clinical or therapeutic applications.

Note: No organism-specific selectivity or inhibitory agents are specified for this item; refer to CoA/Spec Sheet for any formulation details that might confer selectivity.

Buffer Applications

This product is a microbiological growth medium rather than a defined buffering system. Buffer-making guidance is not typically applicable.

• If pH control is critical for your application (e.g., to optimize protease activity visualization), combine the prepared medium with appropriate atmospheric conditions or overlay techniques as per protocol (literature) or select a formulation that includes a defined buffer system.
• Target pH and buffering components for this specific item are Not specified for this item; refer to CoA/Spec Sheet.

Green Alternatives

Sustainability considerations for culture media focus on water-based preparation and minimizing waste.

• Solvent: Water is the sole preparation medium—intrinsically low environmental impact compared with organic solvents.
• Energy use: Autoclaving consumes energy; consolidate sterilization cycles and optimize load capacity to reduce footprint (general laboratory sustainability practice).

Alternative media choices (general comparison; literature):

| Medium type | Proteolysis indicator | Typical background | Notes | | --- | --- | --- | --- | | Casein Agar | Casein hydrolysis (clear halos) | Opaque to translucent | Widely used for caseinase screening | | Skim Milk Agar | Casein + other milk proteins | Opaque white | Economical; strong visual contrast; composition varies by milk source | | Azocasein/Chromogenic media | Colorimetric readout | Colored background | Quantitative; may involve specialized substrates |

Trade-offs:

• Skim Milk Agar may be considered a “greener” alternative when sourced from minimal-processing dairy powders, but composition variability can affect reproducibility.
• Chromogenic substrates can improve quantitation but add cost and potential synthetic dye waste streams.

Waste minimization:

• Prepare only the volume required for near-term use.
• Autoclave spent plates before disposal; segregate biodegradable components where institutional policies allow.

Pharmaceutical Uses

No direct therapeutic or clinical use is implied. In pharmaceutical and biotech settings, casein-containing agar media can be used in research and non-clinical quality functions.

Typical roles (general, literature):

• Microbiological screening of environmental or process isolates for proteolytic activity relevant to bioprocess development.
• Training and method development in microbiology labs for visualizing enzyme secretion phenotypes.

Compliance considerations:

• For GMP/GLP contexts, use lot-specific CoA/Spec Sheet to confirm composition, preparation instructions, and performance testing (if available), and qualify the medium per internal SOPs.

Note: Pharmacopeial status, compendial references, and any specific performance claims are Not specified for this item; refer to CoA/Spec Sheet.

Physical Properties

• Appearance: Not specified for this item; refer to CoA/Spec Sheet.
• pH (dehydrated/solution): Not specified for this item; refer to CoA/Spec Sheet.
• Solubility: Designed to disperse/hydrate in purified water upon heating (general property of dehydrated media; literature). Complete dissolution typically requires boiling/steaming prior to sterilization.
• Gel strength: Determined primarily by agar content (literature). Not specified for this item; refer to CoA/Spec Sheet.
• Melting/solidifying behavior (literature, for agar gels):
  • Melts at ~85–95 °C and solidifies at ~32–40 °C depending on agar composition and concentration.
• Density, refractive index, logP, pKa: Not applicable/Not determined for formulated media.

Notes for practical use (general, literature):

• Medium is supplied dehydrated; properties of the prepared medium (clarity, color, firmness) depend on water quality, concentration, and sterilization conditions.
• Viscosity increases with concentration during heating; avoid local scorching by swirling during dissolution.

Quality & Grades

• Item grade: BioReagent (per Product Data)

What BioReagent typically means (general):

• Suitable for biological and microbiological research workflows, with controlled bioburden and composition appropriate for culture applications.
• May be evaluated for functional performance relevant to microbiology (e.g., growth promotion tests) when applicable; refer to the CoA/Spec Sheet for item-specific performance criteria.

Item-specific notes:

• Purity, additive/stabilizer profile, and performance metrics are Not specified for this item; refer to CoA/Spec Sheet.
• For regulated or QC environments, verify lot-specific attributes (e.g., pH of prepared medium, clarity, gel firmness, growth characteristics of control strains) on the CoA.

Best practices for quality assurance (general):

• Use high-purity water (ASTM Type 1 or 2) to minimize variability.
• Calibrate autoclave cycles; validate sterility and gel characteristics on representative plates each lot.
• Record lot numbers and preparation parameters (mass, volume, sterilization time/temperature, cooling, pouring temperature) to support traceability.

Reaction & Applications

Chemical reaction frameworks are not directly applicable; instead, Casein Agar (G.A) is used in microbiology workflows.

Typical applications (general, literature):

• Detection of protease (caseinase) activity: Proteolytic microbes secrete enzymes that hydrolyze casein in the medium, forming clear halos around colonies after incubation and subsequent visualization (e.g., with acid precipitation for contrast, depending on method).
• Enumeration and selection: Supports growth and differentiation of organisms capable of utilizing casein-derived peptides as a nitrogen/carbon source.
• Enzyme screening: Preliminary screening of environmental or industrial isolates for extracellular protease production.

Practical tips:

• Use properly standardized inoculum densities to compare halo sizes across strains.
• Control plates without proteolytic reference strains help set thresholds for interpretation.
• Incubation temperature and time depend on organism physiology (e.g., mesophiles at ~30–37 °C; psychrotrophs or thermophiles as appropriate; literature guidance). Record conditions to ensure comparability.
• Plate drying: Allow plates to surface-dry in a laminar hood before inoculation to prevent colony spread.

Limitations:

• Some non-proteolytic organisms may grow without forming clear zones; growth alone is not evidence of protease activity.
• Halo formation can depend on pH and ionic strength; standardized preparation improves reproducibility.

Item-specific performance characteristics are Not specified for this item; refer to CoA/Spec Sheet.

Reaction Conditions

Not applicable to chemical reactions. The relevant conditions here are those for medium preparation and microbial incubation (general, literature guidance; not item-specific):

Preparation (literature):

• Disperse the specified mass of dehydrated medium in purified water; heat with stirring to dissolve fully.
• Sterilize by autoclaving at 121 °C for ~15 minutes (liquid cycle). Allow pressure to return to atmospheric before removal.
• Cool to ~45–50 °C and, if required, aseptically add heat-labile supplements. Pour into sterile plates and allow to solidify.

Incubation (general, organism-dependent):

• Typical temperatures: 25–37 °C for mesophiles; adjust for psychrotrophs or thermophiles as needed.
• Duration: 18–72 hours depending on growth rate and halo development.
• Readout: Observe for zones of clearing around colonies indicative of casein hydrolysis; some methods employ acid overlays to accentuate clearing.

Critical variables:

• Medium concentration affects gel firmness and diffusion of enzymes.
• Water quality and pH can influence clarity and protease activity.

Exact mass/volume ratios, target pH, and performance parameters for this item are Not specified for this item; refer to CoA/Spec Sheet.

Safety & Handling

Follow good microbiological and laboratory practices. This item is intended for research use only.

• GHS classification: Not specified for this item; refer to SDS.
• Signal word / H-statements / Pictograms: Not specified for this item; refer to SDS.

General safety notes (literature/best practice):

• Allergen awareness: Contains milk-derived proteins (casein). Avoid inhalation of dust and skin contact if sensitized to milk proteins.
• Dust control: Dehydrated media can form nuisance dust. Handle in a well-ventilated area; minimize dust generation.
• PPE: Lab coat, safety glasses, disposable gloves; respiratory protection if dust becomes significant per risk assessment.
• Thermal hazards: Hot media (~100–121 °C) can cause burns. Use heat-resistant gloves and caution during autoclaving and pouring plates.
• Biological risk post-preparation: Once hydrated/sterile, media can support microbial growth. Treat inoculated plates and spent media as biohazardous; autoclave before disposal.
• Incompatibilities: Avoid strong oxidizers and strong acids/bases contacting the dehydrated blend (general precaution). Keep dry to prevent caking and premature degradation.

First-aid (overview; defer to SDS):

• Inhalation: Move to fresh air; seek medical advice if symptoms persist.
• Skin/eye contact: Rinse with water; remove contaminated clothing; seek medical attention if irritation develops.
• Ingestion: Rinse mouth; do not induce vomiting; obtain medical advice.

Always consult the product-specific SDS for authoritative safety information.

Solvent Selection

As a dehydrated culture medium, Casein Agar (G.A) is intended to be reconstituted in purified water. Classical solvent-selection frameworks for organic synthesis do not apply.

Reconstitution medium (general, literature):

• Solvent: Purified/deionized water. Avoid hard/contaminated water that can affect gel clarity and microbial performance.
• Sterilization: Autoclave after full dissolution unless otherwise specified by the CoA (e.g., if any heat-labile supplements are to be filter-sterilized and added aseptically after cooling).

Practical guidance:

• Heat with stirring to near-boiling to dissolve completely before sterilization. Incomplete dissolution can yield weak or heterogeneous gels.
• After autoclaving, cool to ~45–50 °C before pouring plates to prevent condensation and to protect any optional heat-labile supplements added post-sterilization.

Comparison to alternatives (general):

• Skim Milk Agar: Also used to detect caseinolytic activity, but employs skim milk as substrate; may produce different background opacity and sensitivity.
• Gelatin Agar: Targets gelatinase activity rather than casein proteolysis; lower gel strength at incubation temperatures.

For exact reconstitution mass/volume ratios and target pH, these are Not specified for this item; refer to CoA/Spec Sheet.

Storage & Reconstitution

• Storage conditions (per Product Data): Room temperature; ship Normal.
• Keep container tightly closed in a cool, dry place. Protect from humidity to prevent caking and premature degradation.

Reconstitution (general, literature guidance):

• Use purified/deionized water. Mass/volume ratio, target pH, and any supplements are Not specified for this item; refer to CoA/Spec Sheet.
• Heat with stirring to dissolve completely; autoclave to sterilize unless otherwise directed. Cool to 45–50 °C before pouring plates or adding heat-labile components.

Prepared media handling:

• Store poured plates at 2–8 °C in sealed bags or wrapped stacks to minimize desiccation and contamination; allow to equilibrate to room temperature and dry surface condensation before use (general best practice).
• Avoid repeated thermal cycling of prepared media.

Shelf life:

• Lot-specific expiry and recommended retest intervals are Not specified for this item; refer to CoA/Spec Sheet.

Research Use Note: For research use only.

Structure & Identity

Casein Agar (G.A) is a dehydrated culture medium blend intended for microbiological use. It is a formulated mixture (not a single chemical entity), typically comprising proteinaceous components derived from casein and a polysaccharide gelling agent (agar), along with supporting nutrients and salts depending on formulation.

• SKU: C1528457
• CAS: Not specified for this item; refer to CoA/Spec Sheet.
• Molecular formula: Not applicable (mixture).
• Molecular weight: Not applicable (mixture).
• SMILES: Not applicable (mixture).
• InChIKey: Not applicable (mixture).
• Grade: BioReagent (per Product Data)

Structural features (general, literature):

• Casein: heterogeneous milk protein (phosphoproteins; micellar assemblies) that serves as a nitrogen and amino acid source for microbes.
• Agar: linear galactan polysaccharide (agarose + agaropectin) that forms a thermo-reversible gel, providing a solid growth surface.

2D description in words:

• A solid medium surface (once reconstituted and sterilized) in which the protein substrate (casein) is dispersed within an agar gel matrix. Proteolytic microbes hydrolyze casein locally, producing clear zones around colonies under appropriate conditions (general microbiology literature).

Synthetic Utility

Not a synthetic building block or reagent. Casein Agar (G.A) does not participate in organic transformations and is not used as a solvent or catalyst.

If your project involves downstream analysis of microbial metabolites or enzymes identified using this medium, consult appropriate chemical sections for extraction solvents and derivatization strategies. For purely chemical synthesis endeavors, refer to other catalog categories (e.g., solvents, catalysts, or building blocks).

Target Specificity

Not an antibody, probe, or molecularly targeted reagent. There are no antigens, epitopes, clones, isotypes, or species reactivity specifications associated with this product.