Liposome immunoassay by long-lived fluorescence detection

Abstract

Immunoassay by fluorescence energy transfer from a europium chelate in liposome to allophycocyanin (APC) was demonstrated. Streptavidin or antibody to biotin was bonded to the liposome containing the europium chelate of 2-naphthoyltrifluoroacetone in the bilayer. When the biotin bonded to APC (APC–BT) was added to the prepared liposomes and the long-lived fluorescence (λ_ex 336 nm, λ_em 665 nm, delay time 0.05 ms, gate time 3.9 ms) was measured by a flow system, the fluorescence energy of the europium chelate was found to be transferred to APC–BT and the long-lived fluorescence intensity to increase linearly as the concentration of APC–BT (1–10 µg ml^–1) increased. Further, the intensity decreased competitively with the concentration of biotin (0.1–100 µM) when biotin was added to the liposome solution containing a constant concentration of APC–BT.

References

1. E. Soini and I. Hemmilä, Clin. Chem., 1979, 25, 353.
2. C. M. O'Donnel and S. C. Suffin, Anal. Chem., 1979, 51, 33A.
3. I. Hemmilä, O. Malminen, H. Mikola and T. Lovgren, Clin. Chem., 1988, 34, 2320.
4. J. Briggs, V. B. Elings and D. F. Nicoli, Science, 1981, 212, 1266.
5. F. V. Bright and L. B. McGown, Talanta, 1985, 32, 15.
6. M. N. Kronick and W. A. Little, J. Immunol. Methods, 1975, 8, 235.
7. R. M. Sutherland, C. Dahne, J. F. Place and A. S. Ringrose, Clin. Chem., 1984, 30, 1533.
8. L. E. Morrison, Anal. Biochem., 1988, 174, 101.
9. I. Hemmilä, S. Dakubu, V. M. Mukkala, H. Siitari and T. Lovgren, Anal. Biochem., 1984, 137, 335.
10. I. Hemmilä, Clin. Chem., 1985, 31, 359.
11. E. P. Diamandis, Clin. Biochem., 1988, 21, 139.
12. E. P. Diamandis, R. C. Morton, E. Reichstein and M. J. Khosravi, Anal. Chem., 1989, 61, 48.
13. E. P. Diamandis and T. K. Christopoulos, Anal. Chem., 1990, 62, 1149A.
14. R. C. Morton and E. P. Diamandis, Anal. Chem., 1990, 62, 1841.
15. R. A. Evangelista, A. Pollak, B. Allore, E. F. Templeton, R. C. Morton and E. P. Diamandis, Clin. Biochem., 1988, 21, 173.
16. G. Mathis, Clin. Chem., 1993, 39, 1953.
17. M. N. Kronick and P. D. Grossman, Clin. Chem., 1983, 29, 1582.
18. J. C. Reid and M. Calvin, J. Am. Chem. Soc., 1950, 72, 2948.
19. E. A. Bayer, B. Rivnay and E. Skutelsky, Biochim. Biophys. Acta, 1979, 550, 464.
20. S. Batzri and E. D. Korn, Biochim. Biophys. Acta, 1973, 298, 1015.
21. R. J. Duncan, P. D. Weston and R. Wrigglesworth, Anal. Biochem., 1983, 132, 68.
22. J. T. P. Derksen and G. L. Scherphof, Biochim. Biophys. Acta, 1985, 814, 151.
23. T. Förster, Ann. Phys. (Leipzig), 1948, 2, 55.
24. V. K. Jansons and P. L. Mallett, Anal. Biochem., 1981, 111, 54.