Lactose-3'-sulfate (4-O-(3-O-Sulfo-β-D-galactopyranosyl)-D-glucose) is a biochemical reagent used in glycoscience research, which studies the structure, synthesis, biology, and evolution of sugars. This field covers carbohydrate chemistry, glycan formation and degradation enzymology, protein-glycan recognition, and the role of glycans in biological systems, and is closely linked to fundamental research, biomedicine, and biotechnology.