A core 1 / T antigen (Galβ1-3GalNAcα) on a threonine residue equipped with a biotin tag through an amide bond. 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) on a threonine residue, a tumor-associated carbohydrate antigen and ligand for galectins and the macrophage galactose lectin, with the natural Thr presentation of mucin-type O-glycans. The biotin tag enables immobilization on streptavidin/neutravidin-coated platforms.