A core 1 / T antigen (Galβ1-3GalNAcα) ligand equipped with a biotin tag through a hydrophilic PEG3 spacer. The biotin moiety binds with high affinity to streptavidin and neutravidin, enabling straightforward immobilization on chips, in wells, or on other streptavidin/neutravidin-coated platforms. This compound presents the core 1 O-glycan / T antigen (Galβ1-3GalNAcα), a tumor-associated carbohydrate antigen and ligand for galectins and the macrophage galactose lectin. It is a substrate for sialyltransferases that generate sialyl-T antigens. The biotin tag enables immobilization on streptavidin/neutravidin-coated platforms.