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Test Code 3212 Thyroid Function Cascade, Plasma

Performing Laboratory

Barnes-Jewish Hospital Laboratory


Chemiluminescence Enzyme Immunoassay (CEIA)

Testing Algorithm:

If TSH result is <0.35 mcIUnits/mL or >5.5 mcIUnits/mL, #1806 T4 (Thyroxine), Free will be performed, at an additional charge.

Literature References:

1. Package insert: ADVIA Centaur TSH-3. Bayer Diagnostics, Revision F.
2. Package insert: ADIVA Centaur reference manual. Bayer Diagnostics, Revision D.
3. Package insert: ADVIA Centaur assay manual. Bayer Diagnostics, Revision AT.

Specimen Requirements

Specimen Type: Plasma

Container/Tube: Mint-green top (lithium heparin)

Specimen Volume: Full tube


Day(s) Test Set Up

Monday through Sunday

Turnaround Time:
STAT: 1 hour after receipt in laboratory 
Routine: 4 hours after receipt in laboratory

Reference Values

Hyperthyroid: <0.1 mcIUnits/mL
Euthyroid: 0.35-5.50 mcIUnits/mL
Hypothyroid: >12.0 mcIUnits/mL



0.9-1.8 ng/dL


Literature Reference:

Normal ranges are based on patient comparison histographs and suggested normals given by Bayer Diagnostics.

Package insert: ADVIA Centaur TSH-3. Bayer Diagnostics, Revision F.

Test Classification and CPT Coding


84439-Free T4 (if appropriate)

Additional Information

For BJH Laboratory Use Only

Alternate Tube(s):

1 plain, red-top tube

Analyte Stability:

See Analyte Stability Chart in Special Instructions.

Laboratory Processing Instructions:

Test performed in BJH Chemistry. Centrifuge upon receipt. Make a 1-mL aliquot and deliver to the Centaur. Original tube is stored refrigerated for 1 week.

Specimen Transport Temperature


LOINC Code Information

Name LOINC Code
TSH, Plasma 11579-0
T4, Free 3024-7