This anti-Tg autoantibody IgG ELISA Assay Kit is designed, developed and produced for the quantitative measurement of human anti-Tg IgG autoantibody level in test sample. Assay calibrators, controls and pre-diluted human serum samples containing anti-Tg IgG autoantibody are added to microtiter wells of microplate that was coated with high affinity streptavidin on its wall. The autoantibody reaction will not start until the addition of a biotinylated human Tg Antigens. After the first incubation period, the unbound protein matrix is removed in the subsequent washing step. A horseradish peroxidase-conjugated rabbit anti-human IgG subclass specific antibody (tracer antibody) is added to each well. Sample Types: serum. Range: 20 - 1280 U/mL. Sensitivity: 1 U/mL. Time: 2 hours ? It is a routine practice of measuring serum autoantibodies to thyroglobulin (Tg) and microsomal (TPO) for aid in detecting and monitoring autoimmune thyroid disease. Serum anti-TPO autoantibody and anti-Tg autoantibody are found to be well- correlating with histological changes in Harshimoto's thyroiditis. Clinically, positive anti-TPO autoantibody is detected in patients with chronic thyroiditis (70-90%), primary hypothyroidism (~60%), thyrotoxicosis (~50%) and thyroid tumors (~17%), however, anti-Tg autoantibody is mainly identified in patients with Harshimoto's thyroiditis and Graves' disease (40-70%).