Microbiology Laboratory

 MICROSCOPY/KOH MOUNT OF FUNGAL SPECIMEN

Written by MicroDok

AIM: To digest and look out for fungal elements (hyphae & spores) in fungal specimens prior to their culturing.

MATERIAL/APPARATUS: Fungal specimen, face mask, 10% KOH, microscope, glass slide, cover slip, scalpel blade, inoculating loop, 70% ethanol, Bunsen burner, clean white paper, cotton wool, hand gloves.

METHOD/PROCEDURE

  1. Cover your face with a face mask in order to avoid inhalation of fungal spores during specimen collection (scraping).
  2. Clean the affected area from which the specimen will be collected on the patient’s body with 70% ethanol and allow to dry.
  3. Scrape the affected area onto a clean with paper using a sterile scalpel blade. Make sure not to bleed the patient while doing this, and that the patient’s data are written on the paper prior to the scrapping.
  4. Disinfect the site of collection with 70 % ethanol after the scrapping. This will help to prevent the spread of fungal elements.
  5. Place a drop of the 10% KOH solution on a clean glass slide.
  6. Transfer a small portion/piece of the specimen to be tested, onto the KOH solution using a sterile inoculating loop.
  7. Emulsify the preparation using the inoculating loop, and cover with a cover slip.
  8. Place the prepared slide on an undisturbed surface for about 24 hrs before viewing with the microscope. The time lap is to allow for the KOH solution to act on the specimen, and further enhance the clearing of the keratinized portion of the specimen so that the fungal elements present can be exposed.
  9. View the slide under the microscope using the ×10 and ×40 objective lens.

REPORTING OF THE RESULT:

Look out for the presence of any fungal element (spores & hyphae) in the preparation. Make sure that you examine several fields of the slide before making your final report, so as to clear all doubts. Presence of any fungal element is reported while their absence is reported as thus: No fungal elements seen. 

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MicroDok

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