TSH, Thyrotropin
Up to 24 hours
Electrochemiluminescence (ECLIA)
For TSH with reflex to include Free Thyroxine (FT4), use test code 11162
Accredited NRL Laboratory
Daily
Thyroid Stimulating Hormone (TSH) is the primary, first-line biochemical marker used to assess thyroid function, screen for thyroid diseases, and monitor hormone replacement therapy. Because the pituitary gland strictly regulates the thyroid via a negative feedback loop, minor changes in thyroid hormone levels cause significant, inversely proportional shifts in TSH.
Serum or Plasma
1 mL
Serum Separator Tube (SST, Gold Top) Plain Tube (Red Top) Lithium-heparin Plasma (Green Top) EDTA Plasma (Lavender Top)
No special preparation is required for this test. You may eat, drink, and take your medications as normal, unless instructed otherwise by your healthcare provider.
This test does not require any special collection or pre-analytical handling. Follow routine specimen collection protocols.
| Temperature | Period |
|---|---|
| Room Temperature | 7 days |
| Refrigerated | 14 days at 2 to 8°C |
| Frozen | 24 months at -20°C (as an aliquot, thaw only once) |