Used as a pH indicator in acid-base titrations, particularly in water analysis and biological experiments. It provides a clear color change in the pH range of 7.0 to 8.8, shifting from yellow to blue, making it effective for detecting slight alkalinity. Commonly used in testing aquarium water, swimming pools, and environmental water samples to monitor pH levels. Also employed in laboratory settings for titration endpoints and in culture media to indicate pH changes due to microbial activity.