The colloidal iron staining procedure is often used in place of alcian blue to demonstrate acid mucins due to its greater sensitivity to acid mucins, as well as the ability of the colloidal iron stain to detect acid mucins in small quantities. This is particularly helpful in diagnosing some mesotheliomas and differentiating renal cell carcinomas from other pathological processes. Colloidal iron is most commonly used on tissue samples from the gastrointestinal tract.
