Purification of the dermatan sulfate (DS) from H. pallida (A and B) and C. intestinalis (C and D) on a Mono Q-FPLC column. A and C, the total polysaccharides extracted from ascidians were applied to a Mono Q-FPLC column and purified as described under "Materials and methods". Fractions were assayed by metachromasia (•), and NaCl concentration (- - -). The fractions indicated by horizontal bars were pooled in peaks, denominated P1 and P2 (A) or P1, P2 and P3 (C), dialyzed against distilled water and lyophilized. The vertical arrows indicate the elution of standard mammalian dermatan sulfate (DS) and heparin on Mono Q-FPLC column. B and D, ~15 mg of each peak from Mono Q-FPLC column were applied to a 0.5% agarose gel and run for 1 h at 100 V in 0.05 M 1,3-diaminopropane/acetate (pH 9.0). The polysaccharides in the gel were fixed with 0.1% N-cetyl-N,N,N-trimethylammonium bromide solution. After 12 h, the gel was dried and stained with 0.1% toluidine blue in acetic acid/ethanol/water (0.1:5:5, v/v). As a standard, a mixture of mammalian glycosaminoglycans containing 10 mg each of chondroitin 4-sulfate (CS), dermatan sulfate (DS) and heparin (Hep) was applied in agarose gel.