Purification of anti-acetylcholine receptor antibody from patients with myasthenia gravis.

The purification of specific anti-acetylcholine receptor antibodies from the plasma of 3 patients with myasthenia gravis was achieved by affinity chromatography using an immunoadsorbent of alpha-bungarotoxin-Sepharose 4B covalently linked to acetylcholine receptor extracted from human leg muscle. The specific antibody was eluted with potassium thiocyanate. The antibody characteristics were monitored throughout the purification procedure. The high avidity of the antibodies for the acetylcholine receptor was preserved but there was some loss of lambda light chain specific antibody.