Orange IV is primarily used as a pH indicator in various chemical and biological applications. It changes color depending on the acidity or alkalinity of the solution, making it useful for determining pH levels in experiments. In microbiology, it is employed in culture media to monitor pH changes that indicate microbial growth or metabolic activity. Additionally, Orange IV finds application in histology for staining tissues, helping to differentiate cellular structures under a microscope. It is also utilized in analytical chemistry for titration processes, where it provides a visual endpoint for acid-base reactions. Its vibrant color makes it suitable for educational demonstrations in laboratories to illustrate pH concepts.