Used primarily as a biological stain in histology and microbiology to highlight tissues and cells under a microscope. It is particularly effective in staining connective tissues, aiding in the identification of cellular structures in research and diagnostic settings. Additionally, it finds application in the textile industry as a dye for coloring fabrics, providing a range of brown shades. Its staining properties are also utilized in educational laboratories for teaching purposes, helping students visualize and understand microscopic anatomy.