A β-D-galactose 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 provides a β-anomeric galactose building block for glycoconjugate synthesis, glycomimetic research, and the construction of probes for galactose-recognizing proteins, including galectins and other carbohydrate-binding lectins. Terminal β-Gal residues are also a substrate for glycosyltransferases, including sialyltransferases and fucosyltransferases, enabling enzymatic chain extension.