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Test Code THCAS THYROID CASCADE

Important Note

The results of this assay can be effected due to the consumption of Biotin. Patients should discontinue the use of vitamins or supplements that contain Biotin 12 hours before blood draw. See Resources for more information.

Test subject to Medicare National Coverage Determination (NCD). See Medical Necessity documentation requirements by clicking on Medicare National Coverage Determinations under General Information to left of this screen.

Additional Codes

LAB2103

Performing Laboratory(s)

Porter Hospital Laboratory

University of Vermont Medical Center (T3 Total)

Specimen Requirements

Specimen Type: Blood
Container/Tube: Tiger top, serum gel
Specimen Volume: Full tube, submit 1.5 mL serum
Specimen Minimum Volume: 0.75 mL for full cascade
Collection Instructions:
1. Send specimen in original tube.
2. If there is a delay in transport of >1 hour, centrifuge tube.
3. Centrifuged samples are stable for:
• 1 day at room temperature
• 7 days at 2 – 8ºC

Specimen Transport Temperature

Refrigerated

Test Classification and CPT Coding

TSH 84443

FT4  84439

T3    84480

Test Schedule / Analytical Time / Test Priority / Turn Around Time

Daily / 24 Hours / Available STAT / Routine - 4 Hours

                                                       STAT - 60 Minutes

(Total T3 will be sent to Reference Lab for testing if needed)

Normal Reference Values

See each component.

Critical Values

None

Components

TSH reflex 

Free T4 reflex

Total 3