Lab Test

Thyroglobulin by Mass Spectrophotometry

Test Codes

Mayo: TGMS, EPIC: LAB7615, Beaker:

Department

Send Outs

Instructions

This should only be used as a refelx test for samples with previously unknown TgAb status that prove TgAb positive during immunoassay. See LAB5822 for Thyroglobulin by Immunoassay performed by RYO Special Testing Laboratory.

Specimen Collection Criteria

Collect: One Gold-top SST tube.

Physician Office/Draw Specimen Preparation

Let specimen clot 30-60 minutes then centrifuge to separate serum from cells. Transfer serum to a plastic transport tube and refrigerate (2-8°C or 36-46°F).

Preparation for Courier Transport

Transport: 1.5 mL serum, refrigerated (2-8°C or 36-46°F). (Minimum: 0.75 mL)

Rejection Criteria

Plasma specimens.
Serum separator (SST) specimens.
Severely lipemic, icteric, or grossly hemolyzed specimens.     

In-Lab Processing

Let specimen clot 30-60 minutes then centrifuge to separate serum from cells. Transfer serum to a plastic transport tube and refrigerate (2-8°C or 36-46°F).

Transport: 1.5 mL serum, refrigerated (2-8°C or 36-46°F). (Minimum: 0.75 mL)

Storage

Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): 72 hours
Refrigerated (2-8°C or 36-46°F): 7 days
Frozen (-20°C/-4°F or below): 1 year

Specimen Storage in Department Prior to Disposal:

Specimen retention time is determined by the policy of the reference laboratory. Contact the Send Outs Laboratory with any questions.

Laboratory

Sent to Mayo Clinic Laboratories in Rochester, MN.

Performed

Monday – Friday.
Results available in 4-6 days.

Reference Range

By report.

Test Methodology

Tryptic Protein Fragmentation, purified with Immunocapture, Analysis by Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)

Interpretation

By report.

Clinical Utility

Accurate measurement of serum thyroglobulin (Tg) in patients with known or suspected antithyroglobulin autoantibodies (TgAb) or heterophile antibodies (HAb). Assists in the differential diagnosis of early phase silent thyroiditis versus Graves' disease in patients without thyroid cancer.

CPT Codes

84432
LOINC:  3013-0

Contacts

Last Updated

1/20/2023

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