Used in histology and cytology to detect glycogen and other polysaccharides in tissue samples. When applied, it stains glycogen a reddish-brown color, which can then be further visualized with subsequent stains like periodic acid-Schiff (PAS). Commonly used in diagnosing conditions such as glycogen storage diseases and in examining epithelial cells for abnormalities, including in Pap smears. Also utilized in endoscopic procedures to identify abnormal squamous cells in the esophagus and cervix, aiding in early detection of precancerous lesions.