The Dalmau plate culture technique is a method used in microbiology to observe the morphological characteristics of fungi, particularly yeasts like Candida albicans, under different growth conditions. It helps differentiate between yeast and hyphal forms, which is useful for identifying pathogenic fungi.
Principle:
The technique involves culturing the fungus on a cornmeal agar plate (often with Tween 80) and making a coverslip imprint (Dalmau technique) to observe microscopic morphology.
Procedure:
- Prepare Cornmeal Agar Plate (with or without Tween 80).
- Inoculate the Fungus: Streak the yeast culture in a single line on the agar.
- Place a Sterile Coverslip: Gently press a coverslip into the agar at an angle over the streak.
- Incubate: Keep at 25–30°C for 24–72 hours (some fungi may need longer).
- Observe Microscopically:
- Remove the coverslip and examine under a microscope (400x).
- Look for hyphae, pseudohyphae, blastoconidia (yeast cells), chlamydospores (thick-walled spores).
Interpretation:
- Candida albicans typically produces:
- Germ tubes (in serum, not Dalmau plate)
- True hyphae & pseudohyphae
- Chlamydospores (thick-walled, round, terminal spores)
- Other Candida species (e.g., C. tropicalis) may show only pseudohyphae or yeast forms.
Applications:
- Differentiation of Candida species.
- Study of fungal dimorphism (yeast vs. hyphal forms).
- Diagnostic tool in clinical mycology.
Would you like details on a specific fungal species or modifications of the technique?
