DNase Test Agar - BioReagent

Cat. No.: D1528721

GRADE & PURITY BioReagent

Storage

Room temperature

Shipped In

Normal

Overview

For ribonuclease detection, contains 0.2% DNA

Specifications

Specifications & Purity

BioReagent

Storage

Room temperature

Shipped In

Normal

Grade

BioReagent

Product Line

Biological Products

Application Protocols

General DNase activity test workflow (literature; adapt to SOP and organism requirements). Item-specific preparation parameters are not specified; refer to CoA/Spec Sheet.

• Materials
  • DNase Test Agar plates (prepared freshly), sterile loops/swabs, positive/negative control strains, incubator (35–37 °C), optional 1 N HCl (for non-indicator media).
• Procedure A: HCl-flood method (indicator-free base)
  1. Streak or spot-inoculate plates with test and control strains.
  2. Incubate 24–48 h at 35–37 °C.
  3. Flood plate with enough 1 N HCl to cover the surface; gently rock 3–5 min.
  4. Decant acid safely; read immediately. Clear halos around colonies = DNase positive; uniformly opaque background without halos = negative.
• Procedure B: Dye-based direct readout (methyl green or toluidine blue formulations)
  1. Inoculate as above and incubate 24–48 h.
  2. Read directly: colorless halo (methyl green) or pink/red metachromatic halo (toluidine blue) indicates DNase activity.
• Quality controls
  • Include known positive (e.g., Staphylococcus aureus) and negative (e.g., Staphylococcus epidermidis) strains each run.
• Notes
  • Dry plates before use to prevent inoculum spread.
  • For weak producers, extend incubation or increase inoculum density cautiously; avoid overgrowth that obscures halos.
  • Dispose of acid and biohazard waste per institutional guidelines.

Biological Roles

• Assay focus
  • DNase Test Agar supports growth of diverse bacteria while embedding polymeric DNA as a substrate to assay extracellular DNase (deoxyribonuclease) secretion. DNases hydrolyze phosphodiester bonds within DNA, reducing it to oligo-/mononucleotides that fail to precipitate with acid or to complex with certain dyes.
• Microbial physiology/context (general)
  • Extracellular DNases can aid nutrient acquisition, biofilm remodeling, immune evasion, and horizontal gene transfer. Production varies by species and strain and is influenced by growth phase and medium composition.
• Interpretation (literature)
  • Positive reaction: Zone of clearing or decolorization surrounding growth, often extending into the medium if enzyme diffuses.
  • Negative reaction: No halo; background remains opaque/colored.
• Controls and confounders
  • Include defined positive/negative control strains to confirm medium performance.
  • Highly pigmented colonies or mucoid growth may obscure endpoints; adjust lighting/contrast or use an alternate indicator.
  • Some weak producers require longer incubation or a higher inoculum; however, over-incubation may produce nutrient depletion artifacts. Note: These roles describe biological behavior assayed by the medium; they are informative for research characterization and quality control testing only.

Buffer Applications

Not typically applicable. DNase Test Agar is a culture medium, not a buffering reagent. Prepared media are generally near neutral pH suitable for microbial growth, but specific buffer systems or buffer recipes are outside the scope of this product. For pH adjustments (if required by method or organism), use validated microbiological buffers and document any deviations from standard DNase agar protocols.

Green Alternatives

• Environmental considerations (general)
  • Indicator-based DNase agars (with methyl green or toluidine blue) eliminate the need for post-incubation flooding with strong acid (1 N HCl), reducing corrosive chemical use and neutralization/waste handling. Tradeoff: dye manufacture and potential light sensitivity; some dyes may require specific disposal.
  • Preparing only the volume of medium needed minimizes autoclave energy consumption and media waste. Using stackable, reusable glass Petri dishes (where appropriate) reduces single-use plastics.
  • Where applicable, adopt validated shorter incubations at optimal temperature to save energy while maintaining assay sensitivity.
• Comparison (general, not item-specific)
  • Flooding method: No dye, requires HCl; simple formulation; added acid-waste handling.
  • Methyl green DNase agar: Built-in visual readout; avoids HCl; potential fading in strong light; some organisms may show subtler halos.
  • Toluidine blue DNase agar: Strong metachromatic halos; avoids HCl; dye handling and potential staining of labware. Select the approach balancing safety (acid avoidance), clarity of endpoint for your organisms of interest, and institutional waste policies.

Pharmaceutical Uses

• Role in pharmaceutical/biotech settings (general)
  • DNase Test Agar can be used in non-clinical, research and in-process quality laboratory settings to characterize environmental or process isolates for DNase activity, aiding strain identification or phenotypic profiling. It is not intended for clinical diagnostics.
• Excipient/formulation status
  • Not used as an excipient. No pharmacopeial monograph is associated with this complex mixture.
• Method integration
  • As part of a broader microbial identification workflow, DNase phenotyping may complement tests such as coagulase, hemolysis, pigment production, and carbohydrate utilization.
• Compliance note
  • When used in GMP-adjacent labs, document lot numbers, storage conditions, preparation parameters (water quality, autoclave cycle), and include positive/negative controls per SOP. This listing is designated “For research use only” per Product Data.

Physical Properties

• Item-specific properties from Product Data
  • Appearance: Not specified for this item; refer to CoA/Spec Sheet.
  • Storage Conditions: Room temperature (per Product Data)
  • Shipped In: Normal (per Product Data)
• General/literature properties for dehydrated DNase test media (informational, not item-specific specs)
  • Physical form: Free-flowing, hygroscopic powder intended for reconstitution in purified water; forms a firm gel after sterilization and cooling in Petri plates.
  • Color: Commonly off-white to light beige for non-indicator bases; green-tinged when methyl green is present; violet-blue when toluidine blue is present (formulation-dependent).
  • Solubility: Disperses in cold water; fully dissolves/clarifies with heating. Gelation occurs upon cooling (agar thermo-reversible gel, typical gel point ~35–40 °C, melt ~85–95 °C; literature values for agar).
  • pH (prepared medium): Typically near neutral (literature, often pH 7.2–7.4 at 25 °C for many DNase agars). Exact pH for this item is not specified; refer to CoA/Spec Sheet.
  • Density/bulk density, refractive index, logP, BP/MP: Not applicable/reported for complex dehydrated media; not typically characterized by these parameters. Notes: Numerical specifications (e.g., pH target, fill weight, gel strength) are formulation-specific and are not provided for this listing.

Quality & Grades

• Item-specific
  • Grade: BioReagent (per Product Data)
  • Intended use: For research use only (per Product Data). Not for diagnostic/therapeutic or clinical use.
• What BioReagent grade generally implies (informational)
  • Suitable for laboratory research, microbiology, and routine QC workflows where consistent performance is required.
  • Typical supplier QC for culture media includes: appearance and solubility checks of dehydrated powder, pH of prepared medium, gel strength, sterility after autoclaving, and growth-promotion/inhibition and performance testing (e.g., DNase activity visualization with appropriate test organisms). Specific acceptance criteria for this item are not specified; refer to CoA/Spec Sheet.
• Stabilizers/additives
  • DNase test media may or may not include a built-in indicator (e.g., methyl green/toluidine blue). Presence/level of any indicator for this item is not specified; refer to CoA/Spec Sheet. No additional stabilizers are claimed in Product Data.
• Practical notes
  • For method validation/regulated work, retain lot-specific CoA and, where applicable, perform incoming performance verification with known DNase-positive and DNase-negative control strains (e.g., Staphylococcus aureus vs. S. epidermidis; literature examples).

Reaction & Applications

This section is interpreted as practical laboratory applications relevant to DNase Test Agar (not chemical synthesis reactions).

• Primary application (literature/general)
  • Detection of extracellular deoxyribonuclease (DNase) activity from microorganisms. DNase-positive organisms hydrolyze DNA in the medium, enabling visualization as a clear/halo zone around growth.
• Visualization modalities
  • Indicator-free base: After incubation, flood plate with 1 N HCl to precipitate intact DNA. DNase activity appears as a clear zone around colonies against an opaque background.
  • Dye-containing formulations: Methyl green–DNA complex (green background) decolorizes to colorless around DNase-positive colonies; toluidine blue–DNA shows a pink/red halo (metachromasia) around positives. Choice depends on lab preference and downstream handling (HCl not required for dye-based formats).
• Typical test organisms (controls; literature examples)
  • Positive: Staphylococcus aureus, Serratia marcescens.
  • Negative/weak: Staphylococcus epidermidis, Enterococcus faecalis.
• Practical tips
  • Prepare fresh plates and dry surface condensation before inoculation.
  • Spot-inoculate or streak for isolated colonies; incubate 24–48 h at 35–37 °C (aerobic) unless organism requires different conditions.
  • Always include positive and negative controls each run to verify medium performance.
  • For HCl-flood method, read results promptly after flooding to avoid over-clearing of weak reactions.

Reaction Conditions

Interpreted here as incubation and assay conditions for DNase testing (general literature guidance; not item-specific specifications):

• Plate preparation
  • Dissolve the dehydrated medium in purified water per supplier instructions (exact g/L not specified for this item; refer to CoA/Spec Sheet). Heat to dissolve; autoclave at 121 °C for 15 min; cool to ~50–55 °C; pour plates and allow to set/dry surface condensation.
• Inoculation and incubation
  • Spot-inoculate or streak test organisms onto plate surfaces.
  • Incubate aerobically at 35–37 °C for 18–48 h (optimize per organism). Some strains may require up to 72 h for clear halos.
• Endpoint development
  • Indicator-free base: Flood with 1 N HCl, gently rock 3–5 min. Intact DNA precipitates, turning the medium opaque; DNase-positive zones remain clear.
  • Indicator media: No flooding required; read for decolorization (methyl green) or pink/red metachromatic halos (toluidine blue) around colonies.
• Controls
  • Include DNase-positive and DNase-negative control strains each run to verify performance.
• Reading and documentation
  • Measure halo diameter if semi-quantitation is desired. Photograph plates promptly to record endpoints, especially for dye-based media where contrast can change with time. Note: Exact preparation parameters for this item are not specified; follow label/CoA and institutional SOPs.

Safety & Handling

• Hazard information (from Product 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 safety guidance for dehydrated culture media (informational, not item-specific)
  • Avoid creating dust; fine powders may cause mechanical irritation to eyes, skin, and respiratory tract. Use local exhaust/ventilation and avoid inhalation.
  • Wear appropriate PPE: lab coat, safety glasses, disposable gloves; use a dust mask/respirator if airborne dust may be generated.
  • Microbiological use caution: Once prepared/inoculated, plates and liquid cultures can contain viable microorganisms. Handle using BSL-appropriate practices; disinfect work surfaces; autoclave all biohazardous waste before disposal.
  • Incompatibilities: Store dry and tightly closed; protect from moisture. Avoid strong oxidizers and acids/bases contacting dehydrated powder. For indicator-containing variants, strong light may fade dyes; store in the dark after plate pouring.
  • First aid (general): If inhaled, move to fresh air. In case of eye contact, rinse cautiously with water for several minutes. Wash skin with soap and water. If ingested, rinse mouth with water. Seek medical attention if symptoms persist. Always consult the product’s SDS for authoritative hazard, exposure limits, and emergency procedures.

Solvent Selection

Not typically applicable. DNase Test Agar is a solid culture medium base reconstituted with purified water; it is not used as a solvent. For preparation, use deionized/distilled water meeting microbiological media-grade specifications. If your workflow involves overlay or flooding reagents (e.g., 1 N HCl for DNA precipitation in non-indicator methods), select analytical-grade reagents and follow institutional microbiology guidelines.

Storage & Reconstitution

• Storage (item-specific from Product Data)
  • Store at room temperature. Keep container tightly closed and dry. Ship at ambient conditions.
• Reconstitution/preparation (not specified for this item; refer to CoA/Spec Sheet). General literature guidance:
  • Water quality: Use purified/distilled water suitable for microbiological media.
  • Concentration: Follow label instructions for grams per liter; DNase agars commonly fall in the 35–45 g/L range depending on formulation (literature; not item-specific).
  • Dissolution: Suspend powder in water with stirring; heat to boiling to dissolve completely. Do not overheat indicator-containing media.
  • Sterilization: Autoclave at 121 °C for 15 minutes (standard for agar media) unless label specifies otherwise.
  • Pouring: Cool to ~50–55 °C; pour into sterile Petri dishes; allow to solidify and dry surface condensation before use.
  • Storage of prepared plates: Store inverted at 2–8 °C in the dark (especially for dye-containing plates); use within 2–4 weeks or per lab SOP. Bring to room temperature and dry plates before inoculation.
• Freeze–thaw: Not applicable for dehydrated powder. Avoid moisture ingress; reseal promptly. For prepared plates, do not freeze. Always consult the product label/CoA and institutional SOPs for exact preparation parameters.

Structure & Identity

DNase Test Agar is a complex, dehydrated microbiological culture medium formulated to detect extracellular deoxyribonuclease (DNase) activity. As a mixture, it does not have a single defined chemical structure.

• Item-specific identifiers (from Product Data)
  • SKU: D1528721
  • Product Name: DNase Test Agar
  • Grade: BioReagent
• Chemical identifiers
  • CAS: Not applicable (complex mixture; no single CAS)
  • InChIKey: Not applicable (mixture)
  • SMILES: Not applicable (mixture)
  • Molecular formula: Not applicable (mixture)
  • Molecular weight: Not applicable (mixture)
• Structural features (general/literature description)
  • Typical components of DNase test media include a proteinaceous nitrogen source (e.g., peptone/tryptose), sodium chloride, DNA (substrate), and agar as gelling agent; some formulations incorporate a dye indicator (e.g., methyl green or toluidine blue). Exact composition varies by formulation and is not specified for this item; refer to CoA/Spec Sheet.
  • 2D description (general): Heterogeneous solid composed of polymeric agar (galactose-based polysaccharide) dispersed with peptides/amino acids, salts, and high–molecular weight DNA substrate; no discrete molecular entity predominates.

Synthetic Utility

Not applicable to chemical synthesis. DNase Test Agar is a microbiological medium and does not serve as a reagent, catalyst, or building block in organic synthesis. For laboratory applications, see Reaction & Applications and Application Protocols sections for microbiological testing guidance.

Target Specificity

Not applicable. This product is not an antibody, enzyme inhibitor, or affinity reagent; it is a general-purpose culture medium for detecting extracellular DNase activity across diverse microorganisms. No antigen/epitope, clone, isotype, or species specificity applies.

Frequently Asked Questions

How should this product be stored?

Store at room temperature.