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Free T4 (by dialysis)

Item Value
Available Stat? No
Test code FT4D
Test group Thyroid tests
Performed by Quest
Sendout? Yes
Method Equilibrium dialysis, RIA
Container type Red top preferred, Gold top acceptable
Amount to Collect 4 mL blood
Sample type Serum
Preferred volume 2 mL serum
Min. Volume 0.2 mL serum
Processing notes Refrigerate. Order Quest # 35167
Units ng/dL
Normal range
Prematures, 25-30 weeks, first week of life 0.5-3.3 ng/dL
Prematures, 31-36 weeks, first week of life 1.3-4.7 ng/dL
Cord blood, > 37 weeks 1.2-2.2 ng/dL
Birth-4 days 2.2-5.3 ng/dL
2 weeks-2 years 0.8-2.0 ng/dL
3-20 years 1.0-2.4 ng/dL
21-87 yr 0.8-2.7 ng/dL

First trimester 0.9-2.0 ng/dL
Second trimester 0.8-1.5 ng/dL
Third trimester 0.8-1.7 ng/dL
Synonyms tetraiodothyronine; thyroxine
Stability Room temperature 1 week, refrigerated 1 week, frozen at -20C 4 weeks
Turn around times Test performed Monday-Saturday. Turnaround time: 2-4 days.
Additional information Testing is only indicated if there is a descrepancy between the results for TSH and Free T4.
CPT coding 84439-90
LOINC code 6892-4
Last Updated 6/21/2016 12:21:37
Entry Number 917
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