The Calbiotech Thyroglobulin (TG) Ab ELISA Kit is intended for the detection of IgG antibody to Thyroglobulin (TG) in human serum or plasma.
SUMMARY AND EXPLANATION
Thyroglobulin is a water soluble glycoprotein that is involved in the storage and synthesis of thyroid hormones. The thyroid microsomal antigen has been shown to be the enzyme thyroid peroxidase (TPO). Antibodies to thyroglobulin and or microsomal antigen are present in most patients with goitrous thyroiditis (Hashimoto disease), atrophic thyroiditis and about 70-90% of Graves disease. Antibodies are also found in about half of the patients with primary hypothyroidism and thyrotoxicosis, and 10-20% of patients with simple goiters and thyroid tumors. There is also a relationship between thyroid antibodies and diabetes mellitus. Thyroid autoantibodies are present in about 6-7% of normals and their incidence increases with age. Classically, autoantibodies to thyroid antigens are detected by precipitation reactions, hemagglutination and by immunoflourescence. However the tests are subjective and lack high sensitivity. Enzyme-Linked Immunosorbent Assays (ELISAs) combine greater sensitivity, objective reading and ease of use. ELISAs have been developed and validated for detecting autoantibodies to thyroid antigens.
PRINCIPLE OF THE TEST
Diluted patient serum is added to wells coated with purified TG recombinant antigen. TG specific antibody, if present, binds to the antigen. All unbound materials are washed away and the enzyme conjugate is added to bind to the antibody-antigen complex, if present. Excess enzyme conjugate is washed off and substrate is added. The plate is incubated to allow the hydrolysis of the substrate by the enzyme. The intensity of the color generated is proportional to the amount of TG specific antibody in the sample