Bromophenol blue (BPB) is widely used as a pH indicator in various laboratory applications. It is particularly effective in the pH range of 3.0 to 4.6, where it transitions from yellow (acidic) to blue (basic). This property makes it valuable in titrations to determine the endpoint of acid-base reactions. In microbiology, BPB is employed in agar media to visually monitor pH changes during bacterial growth. It is also used in electrophoresis as a tracking dye to monitor the progress of DNA or protein migration through gels. Additionally, BPB serves as a colorimetric reagent in analytical chemistry for detecting the presence of certain ions or compounds. Its versatility and distinct color change make it a reliable tool in both research and industrial settings.