Investigation on the Determination of Serum Iron Binding Capacity Using Radioactive Iron ⁵⁹Fe (I)

A Method Using Magnesium Carbonate

Abstract

A method of the determination of serum iron binding capacity was investigated using radioactive iron-59. A chemical TIBC kit“Fe test Wako”was used as reagents. Radioiron⁵⁹Fe was added to ferric chloride solution.
0.5 ml of serum was incubated to⁵⁹Feferric chloride (3μg Fe) solution during 10 minutes at 37°C. After the first counting of⁵⁹Feactivity (A cpm), 0.15g of magnesium carbonate was added to the mixture which was kept stand at room temperature for 30 minutes.
After centrifugation, 1 ml of supernatant removed to another counting vial with the same diameter and diluted to the same volume of the intial mixture and counted the⁵⁹Feactivity again (B cpm) .
Then
UIBC (μg/dl) =B×2/A×3×200
From ninety two to ninety seven % of 3μg unbound iron was removed by 0.15 g of magnesium carbonate under the presence of iron saturated serum. While, ⁵⁹Fein unsaturated serum was not precipitated by the same dose of magnesium carbonate.
There were no elution of⁵⁹Fefrom the precipitate of magnesium carbonate and iron colloid mixture to the supernatant.
The data obtained from this method showed excellent linearity and was quite steady for the changes of room temperature and for repeated determination. The correlation between the value of UIBC obtained from chemical and radioiron method by magnesium carbonate was significant.
Mean normal value of UIBC by this method was 200.5±45.9μg/dl, 187.9±43.5μg/dl for male and 205.9±46.3μg/dl for female.
Since this method has quite simple technique and gives correct value of UIBC, it is concluded that this method is suitable and excellent method for the determination of serum iron binding capacity.