Used as a pH indicator in laboratory applications, particularly in gel electrophoresis to monitor the migration of samples. It changes color from yellow to blue as the pH increases, making it useful for visual tracking during DNA, RNA, or protein separation. Also serves as a tracking dye in agarose and polyacrylamide gels, allowing real-time observation of electrophoretic progress. Commonly included in loading buffers to add density and color to samples for easier handling and visualization.