Procion Blue HB is widely used in the textile industry for dyeing cellulose fibers such as cotton, linen, and rayon. It is particularly valued for its bright blue color and excellent wash-fastness, making it suitable for fabrics that require frequent laundering. The dye is also employed in the coloring of paper and leather, providing vibrant and durable hues. In biological research, Procion Blue HB is utilized as a stain in electrophoresis and chromatography to visualize proteins and other macromolecules. Its ability to bind specifically to certain proteins makes it a useful tool in biochemical studies. Additionally, it is sometimes used in histology for staining tissues to enhance microscopic examination.