Anti-sDNA antibody purified from sera of human patients with systemic lupus erythematosus—I

Human SLE sera with anti-nuclear activity were subjected to immunoadsorption with a singlestranded deoxyribonucleic acid (sDNA)-cellulose adsorbant. The antibodies were dissociated from the adsorbant with an equal-molar solution of 4 nucleotides (dAMP. dGMP, dCMP and TMP). Ligand-eluted antibodies were characterized for purity by immunoelectrophoresis and disc gel electrophoresis. Antibody preparations were analyzed for immunoglobulin classes by the capillary precipitin test using class-specific antisera. IgG was the predominant class in all preparations. Purified antibody preparations derived from immunoadsorption were characteristically aggregated as determined by disc-gel electrophoresis and molecular sieve chromatography. The possible sources of aggregation are discussed in detail.