Free T4 Hormones Kit

The âEIA-THYROID-T4 FREE is a one-step immunoasay to determine the presence of free thyroxine (free T4) in human serum using competitive microplate enzyme immunoassay. Plates are coated with anti-T4 antibodies. Serum reference, patient speciment, or control is first added to microplate well. Enzyme-T4 conjugate is added. Free thyroxine present in the sample competes with Enzyme-thyroxine conjugate for binding with anti-T4 coated microplate to form an antigen-antibody complex. Unbound conjugate is removed by washing. The enzyme activity in the antibody-bound fraction is inversely proportional to the native free thyroxine concentration. The enzyme activity is revealed by a color change in TMB-substrate solution.