Test Code T4 T4 (Thyroxine)
Specimen Requirements
Container/Tube: GRN/SST
Preferred: Plasma
Acceptable: Serum
Specimen Volume: 1.0 mL
SPECIMEN PROCESSING and HANDLING
Complete clot formation should take place before centrifugation. Serum or plasma should be physically separated from cells as soon as possible. A maximum limit of two hours from the time of collection is recommended.
TRANSPORT TEMPERATURE
Serum and plasma samples may be stored for up to 5 days at 2–8 °C (36–46 °F) or 4 weeks at -20 °C (-4 °F).
PERFORMING LAB
WKMC, WKB, WKP, WKS