1974 Volume 23 Issue 6 Pages 335-341
Usefulness of Tetralute kit for measuring total serum thyroxine was evaluated.
The characteristics and advantages of this method, compared with other in vitro thyroxine measurements were as follows.
1) Virtually all thyroxine is extracted from the serum by placing it in a strong alkaline Sephadex G-25 column. This procedure can be carried on easily in a short time.
2) Only 0.1 ml of serum specimen is used in this measurement.
3) Such an effect of the differences in incubation time or incubation temperature on the results as seen in methods using resin, was not observed.
4) As the most linear and accurate range of the standard curve was between 2.5 and 10.0μg thyroxine iodine per 100 ml, it was necessary to determine the specimens by increasing the amount of serum with lower concentration of thyroxine iodine than 2.5μg per 100 ml and by decreasing the amount of serum with higher concentration of thyroxine iodine than 10.0μg per 100 ml.
5) A satisfactory reproducibility of the kit was obtained in measuring the serum from the subjects with various thyroid functions and from the pregnant women.
6) The values of the thyroxine iodine concentration (μg/100 ml) ranged 5.53±1.30 in normal subjects, 15.40±3.77 in patients with hyperthyroidism, 1.64±1.21 in patients with hypothyroidism, and 8.07±1.87 in pregnant women. A good correlation between the value of Tetrasorb and that of Tetralute was observed.
From these observations, it was concluded that the Tetralute test was useful screening technique for thyroid function with its simplicity and accuracy, although it was troublesome to change the volume of specimens with lower or higher concentration of thyroxine iodine than 2.5 or 10.0μg/100 ml.
