T4 (Thyroxine), Free
Serum or Plasma
1-2 mL Blood
Light Green (Lithium Heparin PST)
Plasma collected in an EDTA (lavender-top) or serum collected in a (red-top)/serum separator tube (SST) are also acceptable.
0.5 mL Plasma or Serum
0.3 mL Plasma or Serum
Centrifuge and separate plasma or serum. Give to Chemistry Monday-Friday. Place in refrigerator on weekends.