This oligosaccharide has been prepared by high resolution gel filtration of partial endolyase digestion of purified Streptococcal HA. ``dp'' refers to degree of monosaccharide polymerization. Very low in endotoxin. Formula: ?HexAβ1,3 [GlcNAcβ1,4 GlcAβ1,3]8 GlcNAc Uronic acid (HexA) at the non-reducing end of the oligosaccharide has a C4-C5 double bond as a result of the endolyase scission. The C4-C5 double bond absorbs strongly at 232nm and can be used for monitoring the oligosaccharide in various separation systems.