Arkray Lugol's Iodine Reagent is a solution of iodine and potassium iodide in water, commonly used as a staining solution to detect intestinal protozoa and helminth ova or larvae in fecal samples. It is also used as a reagent to detect the presence of starches, which turn a dark-blue/black color upon reaction with Lugol's solution. Additionally, it's used in cancer diagnosis, as it stains glycogen-rich cells brown, highlighting glycogen-depleted cancer cells.