Free Thyroxine (fT4) LIA Assay Kit
Free Thyroxine (fT4) LIA Assay Kit is For Research Use Only
Size: 1×96 wells
Sensitivity: 1 pg/mL
Dynamic Range: 2–80 pg/mL
Incubation Time: 90 minutes
Sample Type: Serum
Sample Size: 25 μL
Assay Principle for Free Thyroxine (fT4) LIA Assay Kit
The principle of the Free Thyroxine (fT4) LIA Assay Kit is a chemiluminescence immunoassay (LIA) test that follows the typical competitive binding scenario. Competition occurs between an unlabelled antigen (present in standards, control and patient samples) and an enzyme-labelled antigen (conjugate) for a limited number of antibody binding sites on the microplate. The washing and decanting procedures remove unbound materials. After the washing step, the luminescence substrate solution is added. The relative luminescence units (RLUs) are measured on a microtiter plate luminometer. The RLU values are inversely proportional to the concentration of fT4 in the sample. A set of calibrators are used to plot a standard curve from which the amount of fT4 in patient samples and controls can be directly read. The labelled T4 (conjugate) employed in this assay system has shown no binding properties towards thyroxine-binding globulin (TBG) and human serum albumin (HSA). The binding sites on the microplates are designed to be of a low binding-capacity in order not to disturb the equilibrium between T4 and its carrying proteins. The assay is carried out under normal physiological conditions of pH, temperature and ionic strength.
SPECIMEN COLLECTION AND STORAGE
Approximately 0.2 mL of serum is required per duplicate determination. Collect 4–5 mL of blood into an appropriately labelled tube and allow it to clot. Centrifuge and carefully remove the serum layer. Store at 4°C for up to 24 hours or at -10°C or lower if the analyses are to be done at a later date. Consider all human specimens as possible biohazardous materials and take appropriate precautions when handling.