KOH Flashcards
1
Q
Introduction to KOH
A
Yeast are present in low numbers in the vaginal tract of many women (approximately 50%) without exhibiting any symptoms. The potassium hydroxide (KOH) procedure is used to identify yeasts in vaginal specimens.
2
Q
KOH Procedure
A
- Mix the specimen well.
- Using a sterile pipette, remove one drop or 10 microliters of
the specimen from the tube. - Place one drop (10 µL) of the specimen on a clean
microscope slide with the patient’s identification number. - Without touching the specimen, add one drop (10 µl) of
10% Potassium hydroxide (KOH) directly to the drop of
specimen on the slide. - Place a coverslip on the drops on the slide.
- Place the slide on a brightfield microscope, focus using low
power (10X), and scan at least 10 fields using high dry
power (40X). - Examine for budding yeast or yeast with pseudohyphae.
- Record results based on your laboratory’s criteria.
3
Q
KOH Procedure vs Wet Mount
A
In a wet mount, yeast cells are trapped in the cellular debris and mucus. In a KOH preparation, much of the cellular debris and mucous have been dissolved, allowing these fungal elements to be more readily observed.