MELZER reagent is a special solution used for the detection of fungal spores in microscopic mycology. It is particularly effective in detecting amyloid, a substance present in the spores of some species of fungi that appears as a blue-black stain under the microscope.

The chemical properties of the reagent result from the combination of chloral hydrate, iodine and potassium iodide. Chloral hydrate acts as a solvent, while iodine and potassium iodide serve as staining agents. The reaction of amyloid with the reagent results in a specific staining that is clearly visible under the microscope.

In addition to mycological research, the MELZER reagent also has applications in medical diagnostics and environmental science, where it is used to identify and classify fungal spores from clinical and environmental samples.