Used in bioconjugation processes to link biotin to proteins, antibodies, or other biomolecules through reactive aniline groups. Facilitates detection and purification in immunoassays and molecular diagnostics. Commonly applied in ELISA, Western blotting, and streptavidin-based capture systems due to strong biotin-streptavidin interaction. Enables targeted labeling in biochemical research and development of diagnostic reagents.