Novel radioassay for anti-thyroperoxidase autoantibodies using protein A coupled magnetizable cellulose particles as an immunoadsorbent

Autoantibodies against thyroid peroxidase (TPO); described initially as thyroid microsomal antigen, are found in most of the patients with autoimmune thyroid disorders. The present study comprised of development, optimization and validation of ‘sandwich’ radioassay for the measurement of TPOAb in human serum. The standardized TPOAb radioassay has maximum binding of 25–30%, non-specific binding of < 0.4%, analytical sensitivity of approximately around 1 IU/ml, acceptable intra- and inter-assay %CV, with a standard working range up to 1400 IU/ml. The in-house developed assay is simple, robust and cost-effective, and therefore can be used for routine measurement of TPOAb in clinical samples.