Used as a pH indicator in analytical chemistry, particularly in complexometric titrations involving metal ions. It exhibits a distinct color change when binding to metal ions such as calcium and magnesium, making it valuable in water hardness testing. Commonly employed in conjunction with EDTA titrations, where it forms a stable complex with metal ions, allowing for accurate determination of endpoint through visible color shift from red to blue. Also utilized in biochemical assays for detecting metal ion concentration changes in solution.