Which additive is used in wet-mount microscopy to help visualize fungal elements?

Potassium hydroxide (KOH) is utilized in wet-mount microscopy to aid in the visualization of fungal elements because it acts as a clearing agent, effectively dissolving keratin and other debris present in the sample. When preparing a wet mount with KOH, the solution breaks down the tissues and cellular components, which allows fungal elements such as hyphae and spores to become more apparent under the microscope. This process enhances the contrast between the fungi and the background, facilitating easier identification of fungal infections or elements in clinical samples.

The other additives mentioned do not serve the same purpose as KOH. Alcohol, for instance, is primarily used for fixation in histological preparations rather than visualization, while saline solution helps maintain osmotic balance but does not enhance the visibility of fungi. Formaldehyde, similarly, is used for tissue fixation and preservation rather than to clear tissues for better microscopy view. Thus, potassium hydroxide is specifically advantageous in this context for its unique ability to improve the visibility of fungal structures.