Effect of chelate reagents on terbium-apotransferrin

The effect of chelate reagents on Tb3+-transferrin was studied at room temp erature and pH 7.4. The results show that the binding of Tb3+ to apotransfe rrin is reversible in 0.1 mol/L N-(2-hydroxyethyl)piperazine-N' -2-ethanesu lfonic acid and pH 7. 4. Ethylenediamine tetraacetic acid, and nitrilotriac etic acid can make Tb3'-transferrin dissociated compIetely. The species of Tb3+ in serum was calculated by using ECCLES program. T-c-transferrin is 21 %, Tb-citrate is 62%, Tb-Asp is 15% when terbium concentration of Tb3+ is s maller than 5 x 10(-5) mol/L.