The Diagnostic Automation, Inc. Anti-Thyroglobulin Chemiluminescence ELISA is intended for the detection and semi-quantitation of antibodies to thyroglobulin in human sera. The assay is to be used to
detect antibodies in a single serum specimen. The results of the assay are to be used as an aid to the
diagnosis of thyroid autoimmune disease.
Three major autoantibodies are important in autoimmune thyroid diseases, including anti-Thyroglobulin
(Anti-Tg), anti-Thyroid Peroxidase (Anti-TPO) and autoantibody to thyroid stimulating hormone receptor
(Anti-TSHR). Thyroglobulin is a water soluble glycoprotein consisting of two polypeptide homodimers of mw 330,000 that is involved in the storage and synthesis of thyroid hormones. Anti-Tg are found about 80% of patients with Hashimoto’s thyroiditis, 60% with Graves’ diseases, 30% thyroid Carcinoma, pernicious anemia or sjogren’s syndrome, 3% to 18% of apparently normal individuals may also have Anti-Tg . Anti-Tg is targeted against thyroglobulin within thyroid gland follicles. Several methods are available for measuring Anti-Tg including quantitative passive hemagglutination, immunofluoresence and ELISA. The DAI ELISA with the high sensitivity and specificity permits the measurement of subclinical levels of antibodies to Tg and eliminates subjective interpretation.
Purified Thyroglobulin antigens are coated on the surface of microwells. Diluted patient serum, calibrators and controls are added to wells, and the Thyroglobulin specific antibodys, if present, bind to
the antigens. All unbound materials are washed away. After adding enzyme conjugate, anti-human IgG
bind to the antibody-antigen complex. Excess enzyme conjugates are washed off, and TMB Chromogenic substrate is added. The enzyme conjugate catalytic reaction is stopped at a specific time. The intensity of the color generated is proportional to the amount of IgG specific antibodies in the sample. The results are read by a microwell reader compared in a parallel manner with calibrator and controls.