Chelated Terbium as a Label in Fluorescence Immunoassay
The use of fluorescent substances to covalently label biological molecules was described as early as 1941 by Coons and co-workers (Coons et al., 1941), who used anthracene isocyanate to label bacterial proteins. Later Coons and Kaplan (1950) introduced fluorescein isothiocyanate (FITC) as a more effective label. FITC has since become widely used as a fluorescent label in immunoassay. Its disadvantages are well recognised, however, and stem principally from the overlap of its emission spectrum with the endogenous fluorescence of plasma, and from its very small Stokes shift (only about 25 nm), which can lead to severe interference from scattered light.
KeywordsFluorescence Lifetime Fluorescence Immunoassay Excited State Population Homogeneous Assay Terbium Complex
Unable to display preview. Download preview PDF.
- Bailey, M.P., Rocks, B.F. and Riley, C., 1986, Theoretical Considerations on the Lifetimes of Labels for Time-Resolved Fluoroimmunoassay, J. Pharm. Biomed. Anal., in press.Google Scholar
- Coons, A.H., Creech, H.J. and Jones, R.N., 1941, Immunological Properties of an Antibody Containing a Fluorescent Group, Proc. Roy. Soc. Exp. Biol. (N.Y.), 47: 200–202.Google Scholar
- Hinshaw, J.C., Toner, J.L. and Reynolds, G.A., 1982, Eur. pat. appl. 82303380.8, Fluorescent Chelates and Labelled Specific Binding Reagents prepared therefrom.Google Scholar
- Sidki, A.M. and Landon, J., 1985, Fluoroimmunoassay and Phosphoroimmunoassay, in “Alternative Immunoassays”, W.P. Collins, ed., J. Wiley, Chichester, 185–201.Google Scholar
- Wieder, I., 1978, Background Rejection in Fluorescence Immunoassay, in: “Immunofluorescence and Related Staining Techniques. Proceedings of the VIth International Conference on Immunofluorescence and Related Staining Techniques.”, W. Knapp, K. Holubar and G. Wick, eds., Elsevier/North-Holland BiomEdical Press, Amsterdam and New York, 67–80, and references therein.Google Scholar