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Test Code FT3 T3, Free

Important Note

This test may be affected by biotin interference. Patients on high dose biotin (5mg/day or more) should not have samples drawn until at least 24 hours after the last biotin administration.

Specimen Type

Serum

Container/Tube

Red Top

Offsite Collection Instructions

1. Collect sample following standard collection methods
2. Within 2 hours of collection the sample must be spun and
aliquoted
3. Transport refrigerated (2 – 8˚C)

Turnaround Time

4 hours

Test Includes

N/A

Preferred Volume

0.5 mL

UCMC Collection Instructions

1. Collect sample following standard collection methods
2. Within 2 hours of collection the sample must be received in
Laboratory Service Center
3. Transport room temperature (15 – 25˚C)

STAT Turnaround Time

N/A

Test Usage

Determination of this hormone concentration may
be useful for the diagnostic differentiation of euthyroid,
hyperthyroid, and hypothyroid states.

Critical Results

N/A

Test Limitations

Furosemide caused increased fT3 findings at the daily
therapeutic dosage level.

Any influence that might affect the binding behavior of the
binding proteins can alter the result of the fT3 tests (e.g. drugs,
NTIs (Non-Thyroid-Illness) or patients suffering from FDH (Familial
Dysalbuminemic Hyperthyroxinemia).

Autoantibodies to thyroid hormones can interfere with the
assay.

Binding protein anomalies seen with FDH (familial dysalbuminemic
hyperthyroxinemia), for example, may cause values which, while
characteristic of the condition, deviate from the expected
results.

Fee Code

30184481

Stability: Room Temp

n/a

Stability: Refrigerated

7 days

Stability: Frozen

1 month

Specimen Minimum Volume

0.2 mL

DAY(S) AND TIME(S) PERFORMED

24 hours, 7 days a week including holidays.

STAT DAY(S) AND TIME(S) PERFORMED

N/A

CPT

84481

Method Name

Electrochemiluminescence immunoassay (ECLIA)

Reference Values

230 – 420 pg/dL

Reject Due To

Whole blood/unspun samples greater than 6 hours will be
rejected.

Synonyms

N/A

Additional Information

N/A

Included in Additional codes

N/A

Coverage Information

N/A