UW Hospital and Clinics Lab Test Directory
| Test Name: |
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T3, Free
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| Test Code(s): |
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FT3
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| CPT Code(s): |
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84481
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| Methodology: |
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Chemiluminescent Immunoassay
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| Request Form: |
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UWHC Laboratory Request Form (UWH 1289220, 4004202); Write in test if not on form.
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| Days Performed: |
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Daily, 24 hours.
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| Turnaround Time: |
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Stat: 1 hour.
Routine: 4 hours.
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Specimen Requirements
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| Specimen: |
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Blood
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| Collection Container: |
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Preferred: Green cap with yellow ring (PST)
Also Acceptable:
Green top,
Red cap with yellow ring (SST),
Red top
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| Collection Volume: |
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Preferred: 2 mL
Pediatrics: 0.4 mL
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| Sample Analyzed: |
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Plasma or serum
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| Volume Required: |
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Preferred: 1 mL
Pediatrics: 0.2 mL
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| Specimen Processing: |
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Centrifuge. If a complete barrier has not formed, transfer cell-free plasma/serum to plastic vial. Refrigerate.
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| Specimen Transport: |
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Transport specimen to UWHC Core Laboratory (B4/220). Transport with coolant pack if coming from outreach location.
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| Stability: |
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Refrigerated: 7 days
Frozen: okay; avoid repeated freeze/thaw cycles
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Interpretation
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Reference Interval:
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| Age |
pg/mL |
| 0 days - 11 months |
2.8-6.5 |
| 1 year - 10 years |
2.6-5.2 |
| 11 years - 17 years |
2.3-4.8 |
| 18 years and up |
2.2-4.0 |
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Free Triiodothyronine Free T3
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