Used in bioconjugation and labeling applications, particularly in affinity-based detection systems. The bromopentyl group enables alkylation of thiol or amine groups on proteins, peptides, or other biomolecules, forming stable covalent bonds. This allows site-specific attachment of biotin to target molecules for use in streptavidin-based detection, such as ELISA, Western blotting, and immunohistochemistry. Due to the extended linker arm, it improves accessibility to streptavidin binding sites, enhancing detection sensitivity. Also employed in the development of probes for studying protein-ligand interactions and in immobilizing biomolecules on solid supports for assays and purification.