REF 24-03
ELISA kit for the quantitative determination of free thyroxin in human serum.
Thyroxin (T4) is one of thyroid gland hormones with molecular weight of 777 Da. Serum free thyroxin assay is significant for thyroid gland function evaluation.
The bulk of serum T4 persists in blood in protein-bound form. Principal T4-binding proteins are thyroxin-binding globulin (TBG), thyroxin-binding prealbumin and albumin. Concentration of free non-bound form of T4 (freeT4) is very low, approximately 0,03% of total concentration of circulating hormone. Namely, free T4 is considered to be responsible for biological activity of the hormone. Free T4 concentration does not depend on concentration of binding proteins and remains normal when TBG levels are either increased (e.g. due to congenital pathology, pregnancy, intake of estrogens and oral contraceptives) or decreased (e.g. due to congenital pathology, administration of androgens and salicylates, or renal insufficiency) and when the binding capacity of proteins is diminished after treatment by salicylates. Thus, free T4 level adequately reflects the actual thyroid status. Concentration of free T4 is above normal in patients with thyroid hyperfunction or after intake of thyroxin preparations; it is below normal level in case of thyroid hypofunction.
| Kit volume, wells (including controls) |
96 |
| Analitical sensitivity, pmol/l |
1,0 |
| Precision: Intra Assay Variation, % |
< 8 |
| Range of evaluated concentrations, pmol/l |
0–100 |
| Incubation time, minutes |
60 |
| Incubation temperature, °Ñ |
37 |
| Shelf life, month |
12 |
