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Test Code STSH Thyroid-Stimulating Hormone-Sensitive (s-TSH), Serum

Reporting Name

TSH, Sensitive, S

Useful For

Screening for thyroid dysfunction and detecting mild (subclinical), as well as overt, primary hypo- or hyperthyroidism in ambulatory patients


Monitoring patients on thyroid replacement therapy


Confirmation of thyroid-stimulating hormone (TSH) suppression in thyroid cancer patients on thyroxine suppression therapy


Prediction of thyrotropin-releasing hormone-stimulated TSH response

Advisory Information

This is a standalone test for sensitive TSH.


If a cascade approach is preferred, order THSCM / Thyroid Function Cascade, Serum, which utilizes a cascaded testing procedure to efficiently evaluate and monitor functional thyroid status. Serum TSH is the first-line test and when the s-TSH result is abnormal, appropriate follow-up tests will automatically be performed.

Specimen Required

Patient Preparation: For 12 hours before this test do not take multivitamins or dietary supplements containing biotin (vitamin B7), which is commonly found in hair, skin, and nail supplements and multivitamins.


Preferred: Serum gel

Acceptable: Red top

Specimen Volume: 0.6 mL

Collection Instructions:

1. Serum gel tubes should be centrifuged within 2 hours of collection.

2. Red-top tubes should be centrifuged and aliquoted within 2 hours of collection.

Specimen Type


Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time
Serum Refrigerated (preferred) 7 days
  Frozen  30 days
  Ambient  7 days

Day(s) and Time(s) Performed

Monday through Sunday; Continuously

Performing Laboratory

Mayo Medical Laboratories in Rochester

Method Name

Electrochemiluminescent Immunoassay

Method Description

The Cobas e immunoassay thyroid-stimulating hormone (TSH) method employs monoclonal antibodies specifically directed against human TSH. A biotinylated monoclonal TSH-specific antibody and a monoclonal TSH-specific antibody labeled with a ruthenium complex react to form a sandwich complex. After the addition of streptavidin-coated microparticles, the complex becomes bound to the solid phase via interaction of biotin and streptavidin. The reaction mixture is aspirated into the measuring cell where the microparticles are magnetically captured onto the surface of the electrode. Application of a voltage to the electrode then induces chemiluminescent emission, which is measured by a photomultiplier.(Package insert: Thyrotropin TSH, Roche Diagnostics Corporation, Indianapolis IN)

Reference Values

0-5 days: 0.7-15.2 mIU/L

6 days-2 months: 0.7-11.0 mIU/L

3-11 months: 0.7-8.4 mIU/L

1-5 years: 0.7-6.0 mIU/L

6-10 years: 0.6-4.8 mIU/L

11-19 years: 0.5-4.3 mIU/L

>20 years: 0.3-4.2 mIU/L

Test Classification

This test has been cleared or approved by the U.S. Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information


LOINC Code Information

Test ID Test Order Name Order LOINC Value
STSH TSH, Sensitive, S 11579-0


Result ID Test Result Name Result LOINC Value
STSH TSH, Sensitive, S 11579-0

Testing Algorithm

See Thyroid Function Ordering Algorithm in Special Instructions.

Reject Due To


Mild OK; Gross reject


Mild OK; Gross OK


Mild OK; Gross OK