Macrocyclic europium-chelate fluorimetric tracer. Prepn and optical properties: L. M. Vallarino et al., Proc. SPIE Int. Soc. Opt. Eng. 1885, 376 (1993). Quantification of Eu3+ in dye: K. Saito et al., Anal. Biochem. 258, 311 (1998). Use as quantitative fluorescent label for glycoproteins: Y. C. Lee et al, Glycobiology 8, 849 (1998); I. L. Deras et al., Carbohydr. Res. 306, 469 (1998).