Very low levels of heparan sulfate fragments are present in medium from HPSE-high cells. (A) Anion-exchange high-performance liquid chromatography of heparan sulfate fragments eluting at 25 minutes (monosulfated oligosaccharides) and 33 minutes (disulfated oligosaccharides) were detected in the medium conditioned by HPSE-high cells. (B) Heparan sulfate fragments were not detected in medium conditioned by HPSE-low cells. Elution positions of the 2AB-derivatives of standard unsaturated heparan sulfate disaccharides are indicated by the numbered arrows in panel A: 1, ΔHexA-GlcNAc; 2, ΔHexA-GlcNAc(6-O-sulfate); 3, ΔHexA-GlcN(N-sulfate); 4, ΔHexA-GlcN(N, 6-O-disulfate); 5, ΔHexA(2-O-sulfate)-GlcN(N-sulfate); 6, ΔHexA(2-O-sulfate)-GlcN(N, 6-O-disulfate). *Peaks representing unknown substances derived from the sample preparation.