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 purple (basic). This property makes it valuable in titrations to determine the endpoint of acid-base reactions. In microbiology, BPB is often incorporated into agar media to monitor pH changes during bacterial growth. Additionally, it is used in electrophoresis as a tracking dye to monitor the progress of nucleic acid or protein migration through gels. Its vivid color change also aids in teaching and demonstrating pH concepts in educational settings.