Used in bioconjugation and labeling applications, particularly for detecting and isolating biomolecules. Enables copper-free click chemistry, making it ideal for live cell labeling due to its fast reaction kinetics and biocompatibility. Commonly used to tag proteins, antibodies, and nucleic acids with biotin for streptavidin-based detection or pull-down assays. The sulfo group enhances water solubility, allowing use in aqueous buffers without organic solvents. Suitable for cell surface labeling, protein-protein interaction studies, and target identification in complex biological samples.