Supplementary Information
Methods
In-Line flow release of the oligosaccharide aldoses
10 mg/ml solutions of the glycoproteins (bovine fetuin and porcine gastric mucin) were injected into an emptied 0.5 ml guard column containing Poros 20 R2 beads (Applied
Biosystems, Warrington, UK) .
A flow of 0.2 ml/min of 50 mM KOH was passed through the column using a GP40 pump, while maintaining the temperature of the column at 50 o
C for 9Hr in a water bath. The flow of alkali was neutralised and desalted in-line with a 9 ml column packed with AG50W-X8 cation exchange resin (Bio-Rad, H+ form). Oligosaccharides were trapped from the eluate on a 500 mg Carbograph SPE cartridge (Alltech, Deerfield, Illinois) preconditioned with 6 ml of 80% acetonitrile (ACN), 0.1% trifluoroacetic acid (TFA) followed by 6 ml of 0.1% TFA. The oligosaccharides were then eluted with 6 ml of 50:50,
ACN: 50 mM ammonium hydrogen carbonate (NH
4
HCO
3
) and lyophilised.
HPLC purification of the fetuin aldoses
The reducing fetuin oligosaccharide mixtures obtained from the in-line release method were injected in milliQ H
2
O 0.5 ml aliquots (~7 mg oligosaccharide mixture) onto a 7.5 x 75 mm
Prosphere P-WAX 10u, 1000Å column and ran over the HPLC sytem using 100% milliQ
H
2
O as eluent A for 11 min followed by a gradient increase to 30% 0.5M NH
4
OAc, pH 5.0, eluent B, over the next 25 min. 1 min fractions were collected and pooled according to the
HPLC trace and MS oligosaccharide confirmation.
Release of the oligosaccharide alditols from the glycoproteins

The oligosaccharides were released from the glycoproteins (10 mg, bovine fetuin and porcine gastric mucin) with 50 mM KOH and 1M NaBH
4 for 16 h at 50 o
C in approximately 10 mL of the solution. Glacial acetic acid was added until pH 5.0 was reached and the sample was desalted with 20 ml of AG50W-X8. The oligosaccharides were released with repeated washing with milliq H
2
O (100 ml). The sample was lyophilized and the remaining borate was removed by repeated distillation (x5) of the borate methyl esters using 1 ml of 1% acetic acid in methanol.