FLUORECARE FREE THYROXINE (fT4)

The fluorecare® fT4, based on the principle of the immunochromatographic assay, is used to detect the concentration of fT4 in human serum or plasma by competitive immunodetection method. The mix-well human serum or plasma is added into the specimen adding hole, the fT4 will binds to the fluoresence-labeled detection antibody in the specimen, to form the fT4
complex, which and residual unbound fluoresence-labeled detection antibody will be diffused along with the nitrocellulose membrane due to the effect of chromatography. In the test line (T) area, the residual unbound fluoresence-labeled detection antibody will be combined with the coated antigen in the detection line area, the higher concentration of fT4 is, the less the aggregation of the residual unbound fluoresence-labeled detection antibody on the detection line, the weaker colour of the fluorescent band under the specific wavelength. The signal intensity of fluorescent antibody is negatively correlated with the concentration of the substance to be measured in the specimens. When the fluoresence-labeled chicken IgY
antibody spreads to the quality control line (C) area, the fluoresence-labeled chicken IgY antibody will bind to the goat anti-chicken IgY antibody coated in the quality control line (C) area , regardless of the presence of fT4 in the specimen , to form a fluorescent band at a specific wavelength. When the reaction is over, the instrument can be used to interpret the results. The
optical density of the test line and the control line will be analyzed by the instrument. Afterwards, the instrument calculates the concentration of the fT4 according to the formerly set calibration curve and displays the results, with pmol/L as a unit.