Native flatbed isoelectric focusing for determining antibody clonotype distribution.

A sensitive method to analyze specific antibody clonotype changes in a patient with systemic lupus erythematosus, who developed autoantibodies to the Ro 60 autoantigen under observation, is described in this chapter. Patient sera collected over several years were separated by flatbed isoelectric focusing (IEF). Following electrofocusing, the gel is now ready to be analyzed by affinity immunoblotting utilizing Ro 60-coated nitrocellulose membrane to determine oligoclonality of the anti-Ro 60-containing sera.