Used as a pH indicator in analytical chemistry, particularly in titrations and colorimetric assays. It changes color from yellow to blue over the pH range of 3.8 to 5.4, making it ideal for monitoring acidic reactions. Commonly employed in biological laboratories to test the pH of urine and other physiological fluids. Also utilized in microbiology as part of culture media to detect acid production by microorganisms. Its clear color transition makes it suitable for educational experiments involving acid-base equilibria.