This chemical is widely used in bioconjugation and labeling applications due to its dual functional groups: an azide for click chemistry and a fluorescein moiety for fluorescence detection. It is particularly useful in bioimaging and cellular studies, where it can be employed to label biomolecules such as proteins, peptides, or antibodies. The azide group allows for efficient and selective conjugation with alkyne-modified targets via copper-catalyzed azide-alkyne cycloaddition (CuAAC), while the fluorescein provides a bright, visible signal for tracking and visualization under a fluorescence microscope. The PEG spacers enhance solubility and reduce steric hindrance, making it suitable for applications in aqueous environments. This compound is also utilized in drug delivery systems, where it can be conjugated to therapeutic agents for targeted delivery and real-time monitoring of their distribution in biological systems. Additionally, it serves as a valuable tool in proteomics and molecular biology research for studying protein interactions and localization within cells.