Two oligosaccharides β-GlcA-(1→3)-β-Gal and α-GalNAc-(1→4)-β-GlcA-(1→3)-β-Gal related to the glycosaminoglycan linkage region were synthesized. Both oligosaccharides, having a 2-aminoethyl aglycon, were biotinylated and used as immunogens to prepare carbohydrate specific monoclonal antibodies. The biotin-conjugated trisaccharide was able to form a complex with streptavidin which could be used directly for immunization.