The biologically active form of free triiodothyronine (free T3, FT3) is only represented by a small fraction (approx. 0.3%). This is the circulating hormone that is unbound (free) from any carrier proteins such as thyroxine-binding globulin (TBG).

ELISA kit information:

• Reactivity: Human
• Sample Type: Serum
• Sensitivity: 0.536 pg/ml
• Reactivity: Free T3, Free Triiodothyronine, FT3