A preliminary microscopic examination of a clinical specimen for the presence of yeast can often provide a rapid means of detecting infections so that treatment can begin. Wet mounts, potassium hydroxide (KOH), India ink preps, and germ tube tests are described below and on the next few pages.
Wet mounts and potassium hydroxide (KOH) preps
Wet mounts and KOH preps are often performed in physicians' offices or clinic laboratories, typically on vaginal secretions. Yeast may be present in the form of blastospores (budding cells-- indicated by the blue arrows in the image) or pseudohyphae (a chain of elongated yeast cells resembling hyphae-- indicated by the red arrow in the image).
KOH can dissolve keratinaceous material; in thick discharges, yeasts may be detected more easily with this preparation. KOH preps are also useful for examining skin, hair, nails, tissue, and respiratory specimens.
