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Test Code FRT4D T4 (Thyroxine), Free by Dialysis, Serum

Reporting Name

T4 (Thyroxine), Free by Dialysis, S

Useful For

Determining thyroid status of sick, hospitalized patients

 

Used where abnormal binding proteins are known to exist

 

Possibly useful in pediatric patients

Method Name

Equilibrium Dialysis/Tandem Mass Spectrometry (MS/MS)

Performing Laboratory

Mayo Medical Laboratories in Rochester

Specimen Type

Serum


Specimen Required


Container/Tube:

Preferred: Red top

Acceptable: Serum gel

Specimen Volume: 2.6 mL

Collection Instructions: Serum must be separated from gel within 4 to 6 hours of draw.

Additional Information: Include name and telephone number of contact physician.


Specimen Minimum Volume

1.2 mL

Specimen Stability Information

Specimen Type Temperature Time
Serum Refrigerated (preferred) 28 days
  Frozen  21 days
  Ambient  7 days

Reject Due To

Hemolysis

Mild OK; Gross reject

Lipemia

Mild OK; Gross reject

Icterus

Mild OK; Gross OK

Other

NA

Reference Values

0.8-2.0 ng/dL

Reference values apply to all ages.

Day(s) and Time(s) Performed

Monday, Wednesday, Thursday; 3 p.m.

CPT Code Information

84439 

LOINC Code Information

Test ID Test Order Name Order LOINC Value
FRT4D T4 (Thyroxine), Free by Dialysis, S 6892-4

 

Result ID Test Result Name Result LOINC Value
8859 T4 (Thyroxine), Free by Dialysis, S 6892-4

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

Secondary ID

8859