Indigodisulfonic Acid Dipotassium Salt is widely used as a biological stain in microscopy, particularly for highlighting cellular structures in tissue samples. Its ability to bind selectively to certain components makes it valuable in histology and pathology for diagnostic purposes. Additionally, it serves as a dye in textile industries, providing vibrant blue hues to fabrics. In analytical chemistry, it is employed as an indicator in titrations due to its distinct color change properties. The compound is also utilized in research laboratories for studying enzyme activity and protein interactions, owing to its compatibility with biochemical assays.