Specimen:
Collect
- One SST
Also Acceptable:
- One Green Top (Li Heparin)
- One Green Top (Na Heparin)
- One Red Top
Submit
- 2 mL (Min:1 mL) Serum . Submit Refrigerated. Submit in a Standard Transport Tube.
Also Acceptable:
- 2 mL (Min:1 mL) Plasma . Submit Refrigerated. Submit in a Standard Transport Tube.
Special Handling
- Allow specimen to clot completely at room temperature
- Avoid Repeated Freeze/Thaw Cycles
- Minimize air exposure
- Separate from cells ASAP
- For patients receiving therapy with high biotin doses (>5 mg/day), no laboratory test specimen should be collected until at least 8 hours after the last biotin administration.
Stability
See Individual Components
Methodology
- See Individual Components
Performed
Mon-Fri
Reported
1-3 Day(s)
CPT Codes
- 84436
- 84479
- 84480
Interpretive Data
Please see report for interpretive data.
Serum T3 Total levels decrease with age. The stated reference range applies to the young adult population. Elderly patients have serum T3 RIA levels 10-15% lower than the stated reference range.
Biotin in specimens taken from patients on high-dose biotin therapy or supplements may interfere with this test and cause inaccurate test results. It is recommended that for patients receiving therapy with high biotin doses (> 5 mg/day), no laboratory test specimen should be collected until at least 8 hours after the last biotin administration.
Serum T3 Total levels decrease with age. The stated reference range applies to the young adult population. Elderly patients have serum T3 RIA levels 10-15% lower than the stated reference range.
Biotin in specimens taken from patients on high-dose biotin therapy or supplements may interfere with this test and cause inaccurate test results. It is recommended that for patients receiving therapy with high biotin doses (> 5 mg/day), no laboratory test specimen should be collected until at least 8 hours after the last biotin administration.
Components
- 2003 - T4 TOTAL
- 2001 - T3 UPTAKE
- 2007 - FTI
- 2187 - T3 TOTAL
Last Updated: May 19, 2025 @ 9:13 am
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