DS disaccharide composition was also analyzed by HPLC-ESI-MS (Figure 6B). The disaccharide composition profile (major and minor disaccharides) of DS isolated from contaminated HP drug product sample was well match with the commercial DS from Celsus Laboratories. The percentage of the major disaccharide, ΔUA-GalNAc4S of DS recovered from contaminated HP drug product and commercial DS sample were 59.9% and 66.5%, respectively. From these data we can clearly conclude that the chondroitinase ABC sensitive component of the contaminated HP product is indeed DS.