Used in histology to detect the presence of iron in tissue sections, particularly in the liver, spleen, and bone marrow. The kit specifically stains ferric iron (Fe³⁺) deposits blue, allowing pathologists to identify abnormal iron accumulation associated with conditions like hemochromatosis, hemosiderosis, or other iron metabolism disorders. Nuclear Fast Red is used as a counterstain to provide contrast by staining cell nuclei red, making it easier to visualize tissue architecture alongside iron distribution. The method is reliable, cost-effective, and widely used in diagnostic laboratories for routine tissue examination.