Identification of the fungus (Aspergillus/Mucor/Rhizopus) by wet mount using LPCB

Identification of the fungus (Aspergillus/Mucor/Rhizopus) by wet mount using LPCB

Aim:

To identify whether the given fungus is Aspergillus or Mucor or Rhizopus based on microscopic characteristics by wet mount method using lactophenol cotton blue stain.

Theory and Principle :

Filamentous fungi are reliably identified by their characteristics microscopic morphology such as shape, size and arrangement of spores and hyphae. Fungi are eukaryotic and range from unicellular yeast to multicellular molds. They reproduce by producing spores.

Common fungi are Aspergillus, Mucor and Rhizopus. They are filamentous and collectively form mycelium. The morphology of the hyphae and spores can be identified using a simple wet mount technique using lactophenol cotton blue stain.

The organism suspended in the stain are killed due to the presence of phenol. Lactic acid preserves fungal structures and cotton blue stains the fungal cell wall.

Requirements :

• Clean grease free slide

• Coverslip

• Forcep

• Teasing needle

• Distilled water

• Lactophenol Cotton Blue

Procedure:

1. Take a clean slide.

2. Place a drop of water on the slide.

 3. With the help of forceps transfer the fungal mycelium.

4. Tease it with needle to separate the filaments (hyphae).

5. Add a drop of lactophenolcotton blue.

 6. Gently place a coverslip avoiding air bubble formation.

7. Observe under low power and high power objective lens.

8. Read the observations and interpret.

Diagram:

Observation;

Filamentous hyphae bearing sporangia were observed.

Results:

Wet mount using lactophenol cotton blue was carried to identify the fungus sample. Hyphae with sporangium bearing sporangiospores were observed. It is likely to be of mucor species.