7-8

Figure 7-8 Precipitation of peroxidase activity by sera from a patient with autoimmune thyroid disease and positive “microsomal” antibodies, and from a control subject without circulating antibodies. TPO was precipitated by primary incubation with human sera, and removal of TPO Ig complexes was achieved by addition of Protein H Sepharose CL 4B. Residual hTPO activity in the supernatant was assayed in a guaiacol assay.