Widely used as a purple dye in textiles and paper industries due to its strong color and affinity for cellulose-based materials. Commonly employed in histology and microscopy as a staining agent for biological samples, helping to enhance contrast in cell structures. Used in microbiology as a selective agent in culture media, inhibiting the growth of certain bacteria while allowing others to grow. Applied in aquaculture and fish farming as a treatment against fungal infections and some external parasites, though its use is regulated in many countries due to potential toxicity and residue concerns. Also utilized in the production of ink, particularly for ballpoint pens and printing inks, where vibrant color and stability are required. Serves as an acid-base indicator in analytical chemistry, showing distinct color changes with pH variation.