CTK Biotech, USA Free T4 ELISA Kit 96 Test

The RecombiLISA Free T4 ELISA Kit is a competitive solid-phase enzyme-linked immunosorbent assay for the quantitative determination of free thyroxine (fT4) in human serum. A competitive solid-phase enzyme-linked immunosorbent assay for the quantitative determination of free thyroxine (fT4) in human serum.

• Sensitivity: 047 ± 0.026 ng/dL at 95% confidence level
• Specificity: <0.001 cross reactivity with l-triiodothyronine at 100 ?g/dL, iodotyrosine at 100 ?g/mL and diiodotyrosine at 100 ?g/mL; 0.75 cross reactivity with d-thyroxine at 10 ?g/dL, respectively
• Accuracy: correlation coefficient 961 ± 0.012 at 95% confidence level
• Intra Assay Precision: CV < 1%
• Inter Assay Precision: CV < 3%
• Shelf life: 18 months
• Open kit stability: 8 weeks at 2-8 °C, or until the expiration date

• Anti-fT4 Ab Coated Microwells
• fT4 Calibrators C1-C6
• HRP-T4 Conjugate
• Wash Buffer (30X Concentrate)
• TMB Substrate
• Stop Solution
• ELISA Working Sheet
• Product insert

TEST PRINCIPLE The RecombiLISA Free T4 ELISA Test is a competitive solid-phase enzyme-linked immunosorbent assay for the quantitative measurement of fT4 in human serum.The RecombiLISA Free T4 ELISA Test is comprised of two key components: 1) Solid microwells pre-coated with anti-fT4 antibody, 2) Liquid conjugate comprised of horseradish peroxidase conjugated with T4 (HRPT4 conjugate).During the test assay, the test specimen and the HRP-T4 conjugate are simultaneously incubated with the microwells coated with anti-fT4 antibody. The free T4 in the patient specimen will then compete with the HRP-T4 conjugate for binding to the anti-fT4 antibodies on the microwell surface. The amount of conjugate bound to the microwell surface is inversely proportional to the concentration of fT4 in the patient specimen.Unbound conjugate are then removed by washing. The presence of the conjugate is shown by the development of a blue color upon the addition of TMB substrate. The reaction is then terminated with Stop Solution and absorbance is determined using a spectrophotometer at 450/620-690 nm. The color intensity reflects the amount of bound HRP-T4 conjugate and is inversely proportional to the amount of fT4 in the patient specimen, within the dynamic range of the assay.A standard curve is then generated on graph paper by plotting the absorbance value for each fT4 calibrator measured at a wavelength of 450/620-690 nm on one axis, versus the concentration of the fT4 standards on the other, and drawing a best-fit line. The fT4 concentration in each specimen is then determined directly using this curve.