This Sabouraud Dextrose Agar (SDA) with Chloramphenicol is a dehydrated powder formulation designed for the selective isolation and cultivation of fungi, including molds and yeasts. It is a widely used medium in clinical, pharmaceutical, food, and environmental microbiology for the detection of fungal contamination.
The medium contains a high concentration of glucose (40 g/L), which provides an acidic environment (pH 5.6 ± 0.2) that favors fungal growth. The high sugar content and acidic pH are inhibitory to many bacteria, but the addition of chloramphenicol (0.1 g/L) further ensures selectivity by inhibiting a broad spectrum of Gram-positive and Gram-negative bacteria, including those that might otherwise grow under acidic conditions.
Chloramphenicol acts by binding to the 50S ribosomal subunit and inhibiting bacterial protein synthesis. It is effective against a wide range of bacteria but does not affect fungi, allowing for the selective isolation of yeasts and molds from mixed samples.
The peptone blend (equal parts animal tissue peptic digest and casein peptone) provides a rich source of nitrogen and nutrients to support fungal growth.
Intended Use
- Selective isolation and cultivation of fungi (molds and yeasts).
- Microbiological testing of pharmaceutical, cosmetic, and food products.
- Clinical specimen testing for fungal pathogens (in vitro).
- Environmental monitoring for fungal contamination.
- For laboratory use only. Not for clinical diagnosis.
Composition (per Liter)
- Peptone Blend (Animal Tissue Peptic Digest and Casein Peptone, equal parts): 10.0 g
- Glucose: 40.0 g
- Agar: 15.0 g
- Chloramphenicol: 0.1 g
- Final pH: 5.6 ± 0.2 at 25°C
Principle of the Medium
- Peptone Blend: Provides carbon and nitrogen sources for fungal growth.
- Glucose: High concentration (40 g/L) supports robust fungal growth and contributes to the acidic pH.
- Agar: Solidifying agent.
- Chloramphenicol: A broad-spectrum antibiotic that inhibits Gram-positive and Gram-negative bacteria, ensuring selective isolation of fungi.
Storage and Shelf Life
- Format: 250 g/bottle, dehydrated powder.
- Shelf Life: 3 years from date of manufacture.
- Storage: Store in a dry, dark place at 2–8°C. Keep tightly closed to prevent moisture absorption
Q: What is Sabouraud Dextrose Agar with Chloramphenicol used for?
A: It is used for the selective isolation and cultivation of fungi (molds and yeasts) from samples that may also contain bacteria. The chloramphenicol inhibits bacterial growth, allowing fungi to grow uninhibited.
Q: Why is chloramphenicol added to this medium?
A: Chloramphenicol is a broad-spectrum antibiotic that inhibits both Gram-positive and Gram-negative bacteria. It is added to suppress bacterial growth, which allows for the selective isolation of fungi from mixed samples.
Q: Why is the pH of this medium acidic?
A: The high glucose concentration (40 g/L) and the natural buffering capacity of the peptones result in an acidic pH of 5.6. This acidic environment is favorable for fungal growth and inhibitory to many bacteria.
Q: How do I prepare the medium?
A: Weigh 65.1 g of powder, add to 1,000 mL of purified water, heat to boiling until completely dissolved, autoclave at 121°C for 15 minutes, cool to approximately 50°C, and pour plates.
Q: What is the shelf life and storage condition?
A: The shelf life is 3 years from the date of manufacture when stored at 2–8°C in a dry, dark place. Keep the bottle tightly closed.
Q: Is this medium intended for clinical use?
A: This product is intended for laboratory quality control and microbiological testing. It is not intended for direct clinical diagnosis. Clinical specimens should be processed according to standard laboratory protocols.
| Parameter | Specification |
|---|---|
| Product Form | Dehydrated powder |
| Package Size | 250 g/bottle |
| Peptone Blend | 10.0 g/L |
| Glucose | 40.0 g/L |
| Agar | 15.0 g/L |
| Chloramphenicol | 0.1 g/L |
| pH | 5.6 ± 0.2 (at 25°C) |
| Sterilization | 121°C for 15 minutes |
| Incubation | 20–30°C, 3–7 days |
| Shelf Life | 3 years |
| Storage | 2–8°C, dry, protected from light |
| Intended Use | Selective isolation of fungi (in vitro) |
