Alizarin Red S is widely used as a biological stain to detect calcium deposits in tissues, making it valuable in histology and pathology studies. It is particularly effective in identifying calcification in bone and cartilage, aiding in research related to osteoporosis and arthritis. In addition, it serves as a pH indicator, changing color in response to varying pH levels, which is useful in chemical and environmental analysis. The dye is also employed in textile industries for coloring fabrics, especially for producing vibrant red and orange shades. Its ability to form stable complexes with metal ions makes it a useful reagent in analytical chemistry for metal ion detection and quantification.