Extracted ion chromatographs (EICs) of 6OST treated products analysed by LC-MS. a. 8 HP/HS disaccharide standards; b. control; c. product from LB shake flask 6OST treatment; d. product from batch A 6OST treatment; e. product from batch B 6OST treatment; and f, product from batch C 6OST treatment. Unsaturated disaccharides standards of heparan sulfate (0S, ΔUA-GlcNAc; NS, ΔUA-GlcNS; 6S, ΔUA-GlcNAc6S; 2S, ΔUA2S-GlcNAc; 2SNS, ΔUA2S-GlcNS; NS6S, ΔUA-GlcNS6S; 2S6S, ΔUA2S-GlcNAc6S; and TriS, ΔUA2S-GlcNS6S, where GlcNAc is N-acetyl-D-glucosamine and ΔUA 4-deoxy-α-L-threo-hexenopyranosyluronic acid).