Total T4 test kit EIAgen

for thyroid diseasesserumplasma

EIAgen Total T4 Kit is a direct solid phase enzyme immunoassay for the quantitative determination of total Thyroxine (T4) in human serum or plasma. The method can be used to measure T4 concentrations over the range of 4 to 300 ng/mL (0.4 to 30 µg/dL). Introduction Measurement of serum thyroxine concentration is generally regarded as an important in-vitro diagnostic test for assessing thyroid function. This importance has provided the impetus for the significant improvement in assay methodology that has occurred in the last three decades. This procedural evolution can be traced from the empirical protein bound iodine (PBI) test (1) to the theoretically sophisticated radioimmunoassay (2). This microplate enzyme immunoassay methodology provides the technician with optimum sensitivity while requiring few technical manipulations. Principle of the Method Sample of serum or plasma is pipetted into the well coated with Streptavidin. The addition of the Biotin-T4 conjugate (Biotin-T4) and of the immunological reaction starter Anti-T4 -HRP conjugate initiates the competitive assay. During the immunological incubation, the T4 of the sample competes with the Biotin-T4 conjugate for the anti-T4 binding sites of the HRP Anti T4 conjugate which, in turn, is bound by the streptavidin coated wells through the biotin moiety. After washing off the non-reacted species, the amount of the immunological complex remained bound to the wells Streptavidin : Biotin-T4 : Anti-T4-HRP is revealed by the incubation with the chromogen/substrate. The blue colour development is then stopped with sulphuric acid,