Widely used in biochemistry and molecular biology for protein labeling and detection. It enables biotinylation of primary amines on proteins and other molecules, facilitating their capture or detection using streptavidin-based systems. Commonly applied in cell surface labeling due to its membrane-impermeable nature, allowing selective tagging of extracellular proteins. Used in pull-down assays to isolate protein complexes and study protein-protein interactions. Also employed in ELISA, Western blotting, and flow cytometry workflows where high sensitivity detection is required. The long spacer arm improves accessibility to streptavidin binding sites, enhancing detection efficiency. Stable in aqueous solutions, making it suitable for labeling under physiological conditions.