Patent ID: 9140695
Filing Date: 2015-09-22
Classification: G01N

Abstract:
1. A method for determining a concentration of thyroglobulin in a biological sample, comprising performing the following steps in sequential order: first, providing a biological sample including unbound thyroglobulin and endogenous autoantibody-bound thyroglobulin; second, adding an immunoglobulin antibody specific for thyroglobulin to the biological sample containing the endogenous autoantibody-bound thyroglobulin such that the unbound thyroglobulin binds with the immunoglobulin antibody to form antibody-bound thyroglobulin; third, enriching the antibody-bound thyroglobulin and the endogenous autoantibody-bound thyroglobulin present in the biological sample to form an enriched fraction of the thyroglobulin, wherein the enriching step is performed by precipitating the antibody-bound thyroglobulin and autoantibody bound thyroglobulin with ammonium sulfate; fourth, identifying the thyroglobulin in the enriched fraction, wherein identifying the thyroglobulin in the enriched fraction further includes digesting the antibody-bound thyroglobulin and the endogenous autoantibody-bound thyroglobulin complexes, and detecting a product of digestion to identify thyroglobulin by mass spectrometry; and fifth, determining the concentration of the thyroglobulin in the biological sample.