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Thyroglobulin by Mass Spectrophotometry (Southeast Michigan Only)

Test Codes

EPIC: LAB1231465, Beaker: XTHYROGLB, MAYO: TGMS

Department

Send Outs

Instructions

This should only be used as a reflex 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 Red-Top (gel tubes/SST are NOT acceptable).

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

Rejection Criteria

• Plasma specimens.
• Serum separator (SST) specimens.
• 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: 1.25 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): 416 days

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 3-6 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

11/22/2024