Beta-D-Gal-(1->3)-beta-D-GlcNAc-(1->3)-beta-D-Gal-(1->4)-D-Glc is a tetrasaccharide comprising residues of galactose, N-acetylglucosamine, galactose and glucose in a linear sequence, all joined by beta-linkages. It is a glucosamine oligosaccharide and an amino tetrasaccharide.