Used primarily in bioconjugation, this chemical serves as a linker to attach fluorescent labels to biomolecules like proteins, peptides, or antibodies. Its NHS ester groups react with primary amines, enabling stable amide bond formation. The PEG6 spacer enhances solubility and reduces steric hindrance, improving labeling efficiency. Commonly applied in fluorescence microscopy, flow cytometry, and immunoassays for tracking and visualizing biological targets. It’s also utilized in drug delivery systems to monitor therapeutic agents in vivo.