A material which is used to verify the performance of an assay intended to be used for the qualitative and/or quantitative detection of multiple thyroid markers associated with thyroid disease in a clinical specimen. Analytes detected may include, but are not limited to free triiodothyronine (FT3), free thyroxine (FT4), thyroid stimulating hormone (TSH) and/or thyroid peroxidase (TPO).