Test Code T4 T4 (Thyroxine), Total
Performing Laboratory
| Greenbrier Valley Laboratory | 304-647-6060 |
| Memorial Hospital Laboratory- Automated Procedures | 304-388-5953 |
| Plateau Medical Center Laboratory | 304-469-8621 |
| Teays Valley Hospital Laboratory | 304-757-1770 |
Specimen Requirements
Memorial, Plateau, and Teays
Plasma- Mint Green, Dark Green Lithium Heparin or Serum- SST gold top, red top
Allow SST or red top to completely clot
Spin and physically separate plasma/serum from contact with cells as soon as possible
4 mL of plasma/serum (minimum 2 mL)
Additional specimen type that can be used ONLY at Greenbrier
EDTA
Specimen Rejection
- Improperly labeled, collected, stored, and transported
- Quantity not sufficient
Additional rejections ONLY at Greenbrier
- Turbid
- Hemolyzed
Storage and Stability
Memorial, Plateau, and Teays
| Room temperature 15-30oC | 8 hrs |
| Refrigerated 2-8oC | 48 hrs |
| Frozen <-20oC | Not specified |
Greenbrier
| Refrigerated 2-8oC | 5 days |
| Frozen <-20oC | 4 weeks |
Avoid repeat freeze thaw cycles
Reference Values
| Memorial, Plateau, Teays | 6.09-12.23 mcg/dL |
| Greenbrier | 6.9-12.23 ug/dL |
Methodology
| Memorial , Plateau, Teays | Chemiluminescent immunoenzymatic competitive assay |
| Greenbrier | Competitive immunoassay |
Days Test Set Up and Turnaround
Monday through Sunday, Continuously
| AM Collection | Expected by 9AM same day |
| Routine | Expected within 24 hrs |
| Stat | Expected within 1 hr |
| Timed | Expected results are test dependant |
CPT Coding
84436