The measurement of iron-binding capacity in serum and purified transferrin with the aid of chemical affinity chromatography.

In a mew method for the estimation of transferrin by iron-binding capacity iron is added as the tartrate in NaCl with about 10 mM bicarbonate. The excess iron is removed by passage through DEAE-Sephadex A-50 previously treated with the iron chelator disodium catechol-3,5-disulphonate. The iron remaining bound to transferrin is measured without protein precipitation by the use of ferrozine. The method is applicable to fresh, frozen, or lyophilized serum, purified transferrin, and some quality control preparations. Validation experiments confirm that transferrin in serum and in pure solution is saturated with iron and give some evidence of specificity. The possible use of commercially available transferrin preparations as analytical reference standards is discussed.