A Galα1-3lactose (α-Gal epitope) ligand equipped with an azide handle through a hydrophilic PEG3 spacer. The terminal azide couples to alkynes via copper-catalyzed azide-alkyne cycloaddition (CuAAC) or to DBCO and related strained alkynes via copper-free click chemistry, forming stable 1,2,3-triazole linkages. This compound presents a terminal Galα1-3 linkage corresponding to the α-Gal epitope (Galα1-3Galβ1-4GlcNAc / Galα1-3lactose), the target of abundant naturally occurring human anti-Gal antibodies and central to xenotransplantation and anti-Gal immunology research.