Preparative isolation of immune complexes from serum by sucrose gradient ultracentrifugation.

Immune complexes were isolated by ultracentrifugation in sucrose gradients (20-65% (w/w]. the centrifugation procedure was demonstrated to be isopycnic. The banding density of the complexes was influenced by the chemical nature and molecular size of the antigen and by the antigen to antibody ratio. The method was applied for preparative isolation of immune complexes from patients with systemic lupus erythematosus, rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis, and uncomplicated psoriasis.