The amino acid glycine is identified as a component of the inner core oligosaccharide in meningococcal lipopolysaccharide (LPS). Ester-linked glycine residues were consistently found by mass spectrometry experiments to be located on the distal heptose residue (HepII) in LPS from several strains of Neisseria meningitidis. Nuclear magnetic resonance studies confirmed and extended this observation locating the glycine residue at the 7-position of the HepII molecule in L3 and L4 immunotype strains.