Useful for detection of dermatophyte or yeast. Scale is collected from advancing edge of a scaling lesion by gently scraping with side of a microscope slide or a scalpel blade. Nail lesions are best sampled by trimming back nail and scraping subungual debris. A drop of 10-20% potassium hydroxide is added to slide, and coverslip is applied. The slide may be gently heated and examined under microscope. This technique can be utilized to identify hyphae in dermatophyte infections, pseudohyphae and budding yeast in Candida infections, and “spaghetti and meatballs” yeast forms in tinea versicolor.