Human bodies have, as endemic organisms, both yeast (Candida albicans) and molds.

What is used as a confirmatory diagnostic test is used when a fungus invades the skin?

a. Potassium hydroxide (KOH) preparations

b. The Forest light

c. Tinea preparations

d. Sodium chloride (Na+Cl-) preparations

The correct answer is a. Potassium hydroxide (KOH) preparations

Explanation:

Potassium hydroxide preparation is a simple test which is carried to identify the fungal infection invaded in skin, nails, vagina, etc. KOH degrade the keratin or mucous present on sample and clears the background which makes fungal cell more visible under the microscope.

In this method sample from infected area is collected and placed in the center of the slide then a drop of KOH is added on it. After this coverslip is put on the sample and the slide is heated gently to increase the reaction rate of KOH. Then the slide containing fungus is examined under the slide. KOH test is used for both yeast and molds. So the right answer is a.