Test Directory

Measurement of thyroglobulin antibody (TgAb) is used to identify patient samples that may be affected by TgAb interference in the measurement of Tg.

Specimen Type: Serum

Collection Container: Gold Top, Serum Separator or Red Top, Plain

Desired Specimen Volume: 1.5 mL

1. Collect serum separator tube or red top plain tube via venipuncture. 

1. Separate serum from cells.
2. Transfer 1.5 mL of serum to a clear aliquot tube.

This test may exhibit interference when sample is collected from a person who is consuming a supplement with a high dose of biotin (also termed as vitamin B7 or B8, vitamin H, or coenzyme R). It is recommended to ask all patients who may be indicated for this test about biotin supplementation. Patients should be cautioned to stop biotin consumption at least 72 hours prior to the collection of a sample.

Transport to the laboratory refrigerated.

See patient report.

Rare amino sequence mutations with Tg could potentially cause a false-low result in the Tg LC-MS/MS assay, if the sequence variation occurs within the tryptic peptide measured by the assay or eliminates the tryptic cleavage site. In the heterozygote state, the result would be an apparent reduction in Tg concentration by about 50%, while the homozygous state no Tg would be detected.