| Ordering Code | 816 |
|---|---|
| Test Name | T3, Free |
| Alias | Free T3 Triiodothyronine, Free |
| Preferred Specimen | Serum |
| Preferred Container | SST (Gold) |
| Other Specimen/Container | Serum in Plain (Red), Plasma in Lithium Heparin (Green-PST), Plasma in Lithium Heparin (Dark Green-PP No Gel) |
| Optimum Volume | 0.5 mL |
| Handling Instructions | All specimen types must be centrifuged within 2 hours of collection. If no gel separation present in tube and testing is delayed, plasma/serum is aliquoted from cells within 2 hours of collection Keep tubes stoppered at all times. |
| Transport Requirements | Oahu: Refrigerated Airline: Refrigerated |
| Specimen Stability | Ambient: 8 Hours Refrigerated: 48 Hours Frozen: 1 Month Frozen samples should be thawed no more than 3 times DO NOT use frost-free freezers. |
| Rejection Criteria | Insufficient quantity, Specimen older than stability limits, Wrong specimen type |
| Avail. Stat | NO |
| Analytic Time | 1 Day |
| Methodology | Chemiluminescent Immunoassay - Competitive |
Reference range(s)
The reference ranges listed below are valid on this date of August 15, 2025.
| Component | Age | Male Norm | Male Critical Low | Male Critical High | Female Norm | Female Critical High | Female Critical Low | Units | Add'l info |
|---|---|---|---|---|---|---|---|---|---|
| T3, Free | ALL | 2.5-3.9 | 2.5-3.9 | pg/mL |