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Test Code
FRT4D
Test Name
Free T4 by Dialysis/Mass Spec
CPT Codes
84439
Expected Turnaround Time
6 - 12 days
Specimen and Container Info

Specimen Type: Serum

Alternate Specimen Type: Plasma

Collection Container: Gold Top, Serum Separator

Alternate Collection Container: Red Top, Plain or Lavender Top (EDTA)

Desired Specimen Volume: 1 mL
Collection Instructions
  1. Collect a gold top, serum separator tube via venipuncture
Processing and Submission Instructions
  1. Separate serum from cells within 45 minutes of collection.
  2. Transfer 1 mL of serum to a clear aliquot tube (screw cap).
Transport Instructions

Transport to the laboratory frozen.
Stability Requirements

Room Temperature

2 days

Refrigerated

5 days

Frozen

1 year

Freeze/Thaw Cycles

 Stable x3
Methodology
Direct dialysis mass spectrometry; high-pressure liquid chromatography/mass spectrometry (HPLC/MS)
Reference Intervals

See patient report.
Limitations
Reference Lab
Labcorp Of America Holdings
Testing Schedule
Routine, 6 times per week
The American Medical Association (AMA) Current Procedural Terminology (CPT) codes published by HNL Lab Medicine are guidelines and are intended for informational purposes only. CPT coding is the exclusive responsibility of the billing entity. View the Terms.
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