ARUP's Laboratory Test Directory
| 0070135: T3 Uptake |
| Test Mnemonic: T3 UP | |
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#ExistMethodology>
Methodology: Electrochemiluminescent Immunoassay
*ExistMethodology> #ExistPerformed> Performed: Sun-Sat *ExistPerformed> #ExistReported> Reported: Within 24 hours *ExistReported> |
| Specimen Required: | |
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#ExistCollect>
Collect: One 4 mL SST. Also acceptable: One 4 mL PST, one 3 mL lavender (EDTA), pink (K2 EDTA), or green (sodium or lithium heparin).
*ExistCollect> #ExistTransport> Transport: 1 mL serum or plasma at 2-8°C. (Min: 0.5 mL) Submit specimen in an ARUP Standard Transport Tube. *ExistTransport> #ExistPedCollectTransport> Pediatric Collection/Transport: 0.3 mL serum or plasma at 2-8°C. *ExistPedCollectTransport> #ExistRemarks> Remarks: Allow serum to clot completely at room temperature. Separate serum or plasma from cells ASAP. *ExistRemarks> #ExistConditions> Unacceptable Conditions: Grossly hemolyzed specimens. *ExistConditions> #ExistStability> Stability: After separation of cells: Ambient: 24 hours; Refrigerated: 8 days; Frozen: 3 months *ExistStability> |
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| Reference Interval: |
| #ExistRefRange> 28-41% uptake *ExistRefRange> |
| Note: | |
| T3 uptake is of little clinical value alone; it is used to determine the Free Thyroxine Index. |
| CPT Code(s): | |
| 84479 |