Czapek-Dox Agar, Semi-Synthetic Medium for Cultivation of Fungi | Catalog No. AS-1188
Czapek Dox Agar
Synonyms: Czapek's Agar, CZA, Czapek-Dox Medium, Czapek Solution Agar, Czapek-Dox Agar (Modified)
Product Information
| Catalog Number | AS-1188 |
| Medium Type | Semi-synthetic, dehydrated |
| Sole Nitrogen Source | Sodium nitrate |
| Sole Carbon Source | Sucrose |
| Appearance (dehydrated) | White to cream, free-flowing powder |
| Appearance (prepared) | Light amber, clear to slightly opalescent gel |
| Final pH (25°C) | 7.3 ± 0.2 |
Overview
Czapek Dox Agar (also known as Czapek's Agar or CZA) is a semi-synthetic solid culture medium designed for the cultivation and study of fungi and selected microorganisms in laboratory environments. The medium contains sodium nitrate as the sole nitrogen source and sucrose as the sole carbon source, making it particularly suitable for organisms capable of utilising inorganic nitrogen.
Originally developed by Czapek and later refined by Dox, this formulation has become a standard medium for qualitative mycological studies, especially for the cultivation and differentiation of saprophytic fungi. Its defined composition allows clear observation of colony morphology, pigmentation, and sporulation characteristics.
AuSaMicS Czapek Dox Agar is manufactured to ensure consistent nutrient composition, reliable buffering capacity, and reproducible performance across routine laboratory and research applications.
Technical Overview & Taxonomic Relevance
Because Czapek Dox Agar restricts usable nitrogen to nitrate and carbon to sucrose, only organisms with the enzymatic capacity to assimilate inorganic nitrogen can grow well on it — a defined-medium logic that makes colony growth itself diagnostic. This principle underlies its long-standing use in fungal taxonomy: Thom and Church's original Aspergillus monograph and Raper and Thom's Manual of the Penicillia both specify Czapek(-Dox) media as reference substrates for colony diameter, texture, and pigmentation comparisons across species. The same selective logic extends to actinomycete studies, following Waksman's use of the medium for soil-isolate characterisation.
Historical Development & Recognised Standing
The medium originates from Czech botanist Friedrich Johann Franz Czapek's 1901–1902 investigations into nitrogen assimilation and protein formation in Aspergillus niger. American biochemist Arthur Wayland Dox refined the formulation in his 1910 study of intracellular enzymes in Penicillium and Aspergillus, introducing sodium nitrate as the defined inorganic nitrogen source — the modification that gives the medium its combined name, Czapek-Dox.
The formulation is catalogued today as NRRL Medium No. 8 by the USDA Agricultural Research Service (ARS) Culture Collection (Peoria, IL), and is specified in the APHA Compendium of Methods for the Microbiological Examination of Foods for qualitative fungal identification procedures — giving it standing as a recognised reference medium rather than a proprietary formulation.
Aspergillus vs. Penicillium: Differentiating Colony Growth on CZA
| Feature | Aspergillus spp. | Penicillium spp. |
|---|---|---|
| Typical growth rate | Rapid, often filling a 9 cm plate in 5–7 days | Moderate; colony margins remain defined longer |
| Conidial colour | Species-dependent — black (A. niger), yellow-green (A. flavus) | Typically blue-green to grey-green |
| Colony texture | Granular to powdery, radiating conidiophores | Velvety to floccose surface |
| Diagnostic reference | Thom & Church (1926), The Aspergilli | Raper & Thom (1949), A Manual of the Penicillia |
Colony descriptions are general taxonomic reference points; actual morphology varies by strain, inoculum density, and incubation conditions and should be confirmed against current taxonomic keys.
Typical Applications
Mycology
- Cultivation of saprophytic fungi
- Growth and taxonomic differentiation of Aspergillus species (colony morphology, conidial colour, sporulation pattern)
- Reference substrate for Penicillium species characterisation
- Observation of colony morphology and pigmentation
Environmental & Soil Microbiology
- Cultivation of soil-associated fungi and actinomycetes
- Qualitative studies of environmental microorganisms capable of nitrate assimilation
Research & Teaching Laboratories
- Demonstration of defined/selective fungal growth media principles
- Comparative growth studies and method development
Principle of the Medium
Czapek Dox Agar provides a chemically defined environment in which sucrose serves as the sole carbon source and sodium nitrate serves as the sole nitrogen source. Only microorganisms capable of utilising nitrate nitrogen can grow efficiently, allowing selective cultivation. The inclusion of mineral salts (dipotassium phosphate, magnesium sulfate, potassium chloride, ferrous sulfate) provides essential ions and contributes to buffering, supporting stable growth conditions.
Key Features & Benefits
- Defined carbon and nitrogen sources for selective fungal growth
- Sodium nitrate as the sole nitrogen source
- Sucrose as the sole carbon source
- Buffered formulation for stable pH during incubation
- Supports characteristic mycelial and conidial development
- Suitable for routine and research mycology workflows
Composition (Typical, per Litre)
| Ingredient | Quantity | Function |
|---|---|---|
| Sucrose | 30.0 g | Sole carbon source |
| Sodium nitrate | 2.0 g | Sole nitrogen source (Dox modification) |
| Dipotassium phosphate | 1.0 g | Buffering agent |
| Magnesium sulfate | 0.5 g | Source of cations |
| Potassium chloride | 0.5 g | Source of essential ions |
| Ferrous sulfate | 0.01 g | Source of cations |
| Agar | 15.0 g | Solidifying agent |
Quantities reflect the standard Czapek-Dox formulation (Czapek, 1901–1902; Dox, 1910) as adapted for solid media; AuSaMicS AS-1188 is manufactured to this reference specification with batch-to-batch consistency confirmed by growth-promotion testing (see COA tab).
Preparation
- Suspend approximately 49 g of dehydrated medium in 1 L of purified water
- Heat with agitation until completely dissolved
- Sterilise by autoclaving at 121 °C for 15 minutes
- Cool to 45–50 °C and pour into sterile Petri dishes
Storage & Stability
- Dehydrated medium: Store at 15–25 °C, dry, protected from moisture
- Prepared medium: Store at 2–8 °C and prevent dehydration
Intended Use
For laboratory research and educational use only. Not for human, animal, diagnostic, or therapeutic use.
Cross-Reference / Equivalent Products
| Supplier | Product Name | Catalog No. |
|---|---|---|
| AuSaMicS | Czapek Dox Agar | AS-1188 |
| Oxoid / Thermo Scientific | Czapek Dox Agar (Modified) | CM0097 |
| BD Difco | Czapek Solution Agar | 233910 |
| Merck / Sigma-Aldrich | Czapek Dox Agar, NutriSelect® Basic | 70185 / C6095 |
Cross-reference numbers are provided for formulation-identity comparison and convenience only; AuSaMicS AS-1188 is an independently manufactured and specified product.
Frequently Asked Questions
- What is Czapek Dox Agar used for?
- It is used for the cultivation, taxonomic study, and differentiation of saprophytic fungi — particularly Aspergillus and Penicillium species — and for qualitative soil and environmental mycology work.
- Why does Czapek Dox Agar use sodium nitrate instead of an organic nitrogen source?
- Restricting nitrogen to nitrate makes the medium selective: only organisms with the enzymatic capacity to assimilate inorganic nitrogen grow well, which is why colony growth on this medium carries taxonomic information.
- Is Czapek Dox Agar the same as Czapek's Agar or CZA?
- Yes — these are common names for the same defined mycological medium formulation.
- Do you provide COA, SDS, and TDS with each order?
- Yes — batch-specific COA, full SDS, and TDS documentation are available; see the tabs above or request current versions from our technical team.
- Is AS-1188 suitable for diagnostic or clinical use?
- No — it is manufactured for laboratory research and educational use only.
Our technical team can confirm current stock, lead time, and reference-strain QC data for your application.
Technical Data Sheet Summary
Document: TDS-AS-1188 — full Technical Data Sheet available as a downloadable Word/PDF document. Summary specifications below.
Identity
| Product Name | Czapek Dox Agar |
| Catalog Number | AS-1188 |
| Medium Type | Semi-synthetic, dehydrated |
| Weighed Quantity | ~49 g/L |
| Final pH (25°C) | 7.3 ± 0.2 |
Quality Control (Performance Testing)
| Test Organism | Inoculum | Expected Result (18–120 h, 25 °C) |
|---|---|---|
| Aspergillus niger ATCC 16404 | ≤ 100 CFU | Good growth; characteristic black conidial colonies |
| Aspergillus flavus ATCC 9643 | ≤ 100 CFU | Good growth; yellow-green sporulation |
| Penicillium chrysogenum ATCC 10106 | ≤ 100 CFU | Good growth; blue-green colony surface |
| Escherichia coli ATCC 25922 | ≥ 10⁴ CFU | No growth to markedly inhibited growth (selectivity check) |
Mode of Action
Sucrose supplies the sole carbon source while sodium nitrate supplies the sole nitrogen source; only organisms capable of nitrate assimilation and sucrose utilisation proliferate. Dipotassium phosphate buffers the medium, and magnesium sulfate, potassium chloride, and ferrous sulfate supply essential trace ions supporting mycelial growth and sporulation.
Storage & Stability
- Dehydrated medium: store at 15–25 °C, dry, protected from moisture
- Prepared medium: store at 2–8 °C; prevent dehydration; typical shelf life per batch-specific COA
Literature / References
- Czapek, F. (1901–1902). Untersuchungen über die Stickstoffgewinnung und Eiweifsbildung der Pflanzen. Beiträge zur chemischen Physiologie und Pathologie, 1(12), 538–560.
- Dox, A.W. (1910). The intracellular enzyms of penicillium and aspergillus: with special reference to those of Penicillium camemberti. Bulletin (United States Bureau of Animal Industry), 120, 37.
- Thom, C. & Church, M.B. (1926). The Aspergilli. Williams & Wilkins.
- Raper, K.B. & Thom, C. (1949). A Manual of the Penicillia. Williams & Wilkins.
- Waksman, S.A. (1961). The Actinomycetes, Vol. II. Williams & Wilkins.
- American Public Health Association (APHA). Compendium of Methods for the Microbiological Examination of Foods, current edition — fungal enumeration and identification methods.
- USDA Agricultural Research Service (ARS) Culture Collection. NRRL Medium No. 8 — Czapek's Solution Agar. National Center for Agricultural Utilization Research, Peoria, IL.
Safety Data Sheet Summary
Document: SDS-AS-1188 — full 16-section GHS-compliant Safety Data Sheet (Australian regulatory format) available as a downloadable Word/PDF document.
Product & Company Identification
| Product Name | Czapek Dox Agar |
| Catalog Number | AS-1188 |
| Recommended Use | Laboratory culture medium for research and education; not for diagnostic, therapeutic, or human/animal use |
| Manufacturer | AuSaMicS Pty Ltd, Melbourne, Victoria, Australia |
Hazard Overview
Dehydrated culture media of this type are generally regarded as having low acute hazard, but the full SDS should always be consulted before handling. Typical hazard considerations relate to dust inhalation and mechanical/eye irritation from the dry powder; the prepared (autoclaved) gel presents minimal chemical hazard. This summary is not a substitute for the complete SDS.
- Physical form: Dehydrated powder — minimise dust generation during weighing and reconstitution
- Biological hazard: Not a biological hazard as supplied (unused, sterile-dehydrated medium); becomes a potential biohazard only after inoculation and incubation with microorganisms
First Aid & Handling Highlights
- Eye contact: Rinse cautiously with water for several minutes
- Skin contact: Wash with soap and water
- Inhalation: Remove to fresh air; avoid generating dust during handling
- Handling: Use appropriate PPE (gloves, safety glasses); weigh in a fume hood or with local exhaust ventilation where practical; autoclave before disposal if inoculated
This is a summary for quick reference only. Always consult and follow the complete, current Safety Data Sheet before use, handling, storage, or disposal — particularly after inoculation, where standard microbiological biosafety practices apply.
Certificate of Analysis
Each batch of AS-1188 is supplied with a batch-specific Certificate of Analysis confirming compliance with the specifications and growth-promotion results below.
| Test | Specification | Typical Result |
|---|---|---|
| Appearance (dehydrated) | White to cream, free-flowing powder | Conforms |
| Appearance (prepared) | Light amber, clear to slightly opalescent gel | Conforms |
| Final pH (25°C) | 7.3 ± 0.2 | Reported per batch |
| Gel strength / clarity | Firm gel, good clarity | Conforms |
| Growth promotion — Aspergillus niger ATCC 16404 | Good growth, ≤ 100 CFU inoculum | Reported per batch |
| Growth promotion — Penicillium chrysogenum ATCC 10106 | Good growth, ≤ 100 CFU inoculum | Reported per batch |
| Selectivity — Escherichia coli ATCC 25922 | No growth to markedly inhibited | Reported per batch |
Batch Traceability
Batch/lot number, manufacture date, and re-test/expiry date are printed on the product label and the corresponding Certificate of Analysis issued with each shipment. Quote your batch number when requesting a COA reprint.