Naphthofluorescein is widely used as a fluorescent dye in biological and chemical research. It is particularly valuable in fluorescence microscopy and imaging techniques to label and track specific molecules or cellular structures. Its strong fluorescence properties make it suitable for studying dynamic processes in live cells, such as membrane permeability and intracellular transport. Additionally, it is employed in assays to detect and quantify enzymatic activity, as its fluorescence can change in response to specific biochemical reactions. Naphthofluorescein is also utilized in environmental monitoring to trace pollutants or analyze water quality due to its sensitivity to pH and other environmental factors. In material science, it serves as a fluorescent marker to study the properties and behavior of polymers and other materials.