Strong anion-exchange HPLC analysis of the disaccharides formed by chondroitin ABC lyase digestion of ascidians dermatan sulfate. A mixture of standards disaccharide (A) and disaccharides formed by exhaustive action of chondroitin ABC lyase on dermatan sulfate from Herdmania pallida (B) and C. intestinalis (C) were applied to a 25-cm × 4.6-mm Spherisorb-SAX column, linked to an HPLC system. The column was eluted with a gradient of NaCl as described under "Materials and methods". The eluant was monitored for UV absorbance at 232 nm. The numbered peaks correspond to elution positions of know disaccharide standards: peak 1, ΔHexUA-GalNAc; peak 2, ΔHexUA-GalNAc(6S); peak 3, ΔHexUA-GalNAc(4S); peak 4, ΔHexUA(2S)-GalNAc(6S); peak 5, ΔHexUA-GalNAc(4S, 6S); peak 6, ΔHexUA(2S)-GalNAc(4S); peak 7, ΔHexUA(2S)-GalNAc(4S, 6S).