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Test Code FRET4 T4, FREE

Important Note

The results of this assay can be falsely elevated 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

LAB127

Performing Laboratory

Porter Hospital Laboratory

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
• 14 days at 2 – 8ºC

Specimen Transport Temperature

Refrigerated

Day(s) Performed

Daily

Test Classification and CPT Coding

84439

Normal Reference Values

21 and older: 0.50-1.50 ng/dL

<21: See report

Critical Values

None