Carbol fuchsin is widely used in microbiology as a staining agent, particularly in the Ziehl-Neelsen staining technique for identifying acid-fast bacteria, such as Mycobacterium tuberculosis. It penetrates the waxy cell walls of these bacteria, allowing them to retain the stain even after decolorization with acid-alcohol. This property makes it essential for diagnosing tuberculosis and other mycobacterial infections. Additionally, it is used in histology to stain certain tissue components and in dermatology for treating fungal infections due to its antifungal properties. Its versatility in staining and antimicrobial applications makes it a valuable tool in both clinical and laboratory settings.