Test Overview
Test Methodology


Test Usage

Measurement of thyroglobulin (Tg) is useful in the detection of residual or recurrent thyroid cancer. Many individuals develop auto-antibodies to Tg (Tg Ab) and the presence of Tg Ab interferes with the measurement of immunoassay Tg. It is therefore necessary to identify the presence/absence of Tg Ab before measuring Tg. The panel will first measure Tg Ab; if the patient is Tg Ab negative, Tg will be measured using a Second Generation immunoassay with increased low-level sensitivity to 0.05 ng/mL. If the Tg Ab is positive, Tg will be measured by tandem mass spectroscopy. The LC/MS/MS assay will provide quantitative measurement of Tg in the presence of Tg Ab.

Reference Range *

< or = 1 IU/mL

Test Details
Days Set Up
Monday - Friday
Analytic Time

8-10 days

Soft Order Code
MiChart Code
Thyroid Cancer Monitoring (Sendout)
Reference Laboratory
Quest Valencia 90814
Special Testing
Specimen Requirements

Collect specimen in an SST or red top tube. Centrifuge, aliquot serum into a plastic vial and freeze.Specimen should be drawn at least 8 hours after last biotin administration.

Rejection Criteria
Hemolyzed, icteric, or lipemic specimens are not acceptable. Plasma is not acceptable.
Yellow Top Tube
Normal Volume
2.5 mL serum
Minimum Volume
1.5 mL serum
Storage Temperature
Frozen 28 days, Ambient 6 days, Refrigerated 7 days.
Additional Information

Test includes Thyroglobulin Antibody. If Thyroglobulin Ab result is < or = 1 IU/mL, then Thyroglobulin, Second Generation (Beckman Coulter) will be performed at an additional charge (CPT 84432). If Thyroglobulin Ab result is >1 IU/mL, then Thyroglobulin, LC/MS/MS will be performed at an additional charge (CPT 84432). By ordering this test the clinician acknowledges that additional reflex testing will be performed and billed at a separate additional charge if indicated. Test sent to Quest Diagnostics Nichols Institute of Valencia.

CPT Code
Fee Code
NY State Approved