Abstract: In order to remove the anti DNAantibody from the blood of patients with systematic lupus erythematosus(SLE), DNAimmunoadsorbent was prepared by coupling calf thymus DNAto epichlorohydrin activated cellulose beads.The methods and conditions for activation of carrier beads, DNAcoupling and adsorption with patient's plasma were investigated.The activation level was found to be dependent on the NaOHconcentration, amount of offered epichlorohydrin and the molar ratio between NaOHand epichlorohydrin.One milliliter of cellulose beads was activated by incubation with0.5 mLof epichlorohydrin and2.0 mLof2.0-3.0 mol/L NaOHsolution at40 ℃ for2 h, and the activation level was60_100 μmol/mLbeads.DNAcoupling was found to be strongly dependent on temperature and pH.The optimal coupling conditions were0.1 mol/L Tris HCl buffer, pH7.9-8.0 and70-90 ℃. High activation level, high DNAconcentration and long reaction time were also required.Under the optimal condition, 2.0-3.0 mg of DNAcould be coupled to1.0 mLof cellulose beads.In vitro adsorption tests showed that incubation of1.0 mLof adsorbent with3.0 mLof plasma could remove40%-70% of anti DNAantibody from the plasma

Key words: Bead type cellulose, DNA coupling, Immunoadsorbent, Epichlorohydrin activation, Systematic lupus erythematosus