Used in affinity purification, protein labeling, and proximity labeling techniques such as APEX tagging due to its reversible binding to streptavidin and the phenol group's reactivity with peroxidases and hydrogen peroxide to generate radicals that label nearby proteins. Enables gentle elution of target biomolecules without denaturation. Commonly applied in pull-down assays, proteomics research, isolation of protein complexes, and analyzing protein interactions within cells. Its phenol group allows for easy conjugation to other molecules, making it useful in developing detection probes and diagnostic tools.