Used in bioconjugation applications, particularly in click chemistry due to its strained alkyne group that reacts rapidly and selectively with azides via copper-free click reactions. Its bis-PEG linker provides water solubility and flexibility, making it ideal for modifying biomolecules like peptides, proteins, and antibodies without compromising their activity. Commonly employed in the development of antibody-drug conjugates (ADCs), targeted imaging probes, and functionalized nanoparticles. The PEG spacers enhance stability and reduce aggregation in biological environments, while the dual reactive ends allow for symmetrical crosslinking or labeling strategies in diagnostic and therapeutic applications.