A proposed fluorimetric determination of unsaturated iron-binding capacity.
A completely new method for the analysis of uncombined iron-binding capacity (UIBC) in human serum is proposed. The method is based on the discovery by C. K. Luk that the fluorescence of terbium ion (Tb-3+) is enhanced enormously when it binds to an empty Fe-3+ binding site of transferrin. Tb-3+ cannot displace Fe-3+ from an occupied binding site on transferrin. The analytic procedure is to dilute the serum (in order to lower its ultraviolet absorbance), add a solution of Tb-3+, excite with ultraviolet radiation, and measure the intensity of the resulting green fluorescence. With proper calibration this intensity is a measure of UIBC. Analyses of 65 serum samples previously measured at a hospital laboratory show no obvious difficulty with the method. Its absolute accuracy has not been probed in detail.
D001665:Binding Sites / Q000528:radiation effects; D001667:Binding, Competitive; D001798:Blood Proteins / Q000378:metabolism; D006801:Humans; D007501:Iron / Q000378:metabolism*; D008970:Molecular Weight; D013050:Spectrometry, Fluorescence / Q000379:methods*; D013725:Terbium / Q000378:metabolism; D014168:Transferrin / Q000378:metabolism*; D014466:Ultraviolet Rays
D001798:Blood Proteins; D014168:Transferrin; D013725:Terbium; D007501:Iron