KOH test

The KOH test is a procedure in which potassium hydroxide (KOH) is used to detect fungi by dissolving human cells in a culture. The difference in cell wall composition of human cells and fungal cells allows this procedure to help distinguish the two cells. KOH denatures the proteins in the human cell; only the fungal cells remain to be seen under the microscope.

KOH test procedure:


 * 1) Take scraping from margin (not center) of lesion
 * 2)  Place on clean slide
 * 3)  Add 2-3 drops of 10% KOH in water
 * 4)  Warm the slide (don't boil)
 * 5)  Optional - add 1 drop of lactophenol cotton blue
 * 6)  Add cover slip
 * 7)  Examine immediately under high dry magnification with light microscope