Used as a pH indicator in acid-base titrations, particularly effective in two pH ranges: 1.2–2.8 (red to yellow) and 8.0–9.6 (yellow to blue). Commonly applied in educational labs to demonstrate pH changes and in analytical chemistry for determining acidity or alkalinity of solutions. Also utilized in microbiology media to detect pH shifts caused by microbial activity. Its dual transition range makes it suitable for detecting both strong acid-strong base and weak acid-strong base reactions.