Anti-thyroglobulin analysis (Anti Thyroglobulin - A-TG) is a test that measures the level of antibodies against thyroglobulin in the blood. It is mainly used to diagnose and monitor thyroid gland conditions, such as autoimmune thyroiditis (Hashimoto’s disease) and thyroid tumors. Elevated levels of these antibodies may indicate disorders in thyroid function and require further medical evaluation.