Ion Exchange Fractionation of Serum
BioSepra Q Ceramic Hyper D F ion exchange sorbent beads (Ciphergen Biosystems Incorporation, Fremont, CA).
96-Well sample plates (Nalge Nunc International, Rochester, NY).
96-Well Silent Screen filter plates with Loprodyne membrane filter (0.45 µm pore size; Nalge Nunc International).
96-Well collection plates (Nalge Nunc International).
50 mM Tris-HCl buffer at pH 9.0 (W1 ion exchange bead washing buffer).
50 mM Tris-HCl buffer containing 9 mol/L urea and 20 g/L CHAPS (3,3-cholmido-propyl-dimethylammonio-1-propanesulfonate) (D1 sample denaturing buffer) at pH 9.0.
50 mM Tris-HCl buffer containing 1 mol/L urea and 2.2 g/L CHAPS at pH 9.0 (Q1 bead equilibration buffer).
50 mM Tris-HCl buffer containing 1 g/L N-octyl-β-D-glucopyranoside (OGP) at pH 9.0 (E1 elution buffer).
100 mM Sodium phosphate containing 1 g/L OGP at pH 7.0 (E2 elution buffer).
100 mM Sodium acetate containing 1 g/L OGP at pH 5.0 (E3 elution buffer).
100 mM Sodium acetate containing 1 g/L OGP at pH 4.0 (E4 elution buffer).
50 mM Sodium citrate containing 1 g/L OGP at pH 3.0 (E5 elution buffer).
33.3% Isopropanol, 16.7% acetonitrile, and 0.1% trifluoroacetic acid (E6 elution buffer).
Micromix 5-01 shaker (Euro/DPC Ltd., Gwynedd, UK).