Patent ID: 7087384

Claim:
A process for reducing the fluorescence quenching caused by the measuring medium in a fluorescence assay of an analyte using at least one fluorescent label, comprising introducing a rare earth metal macropolycyclic complex into the measuring medium, the complex comprising at least one rare earth metal ion complexed with a macropolycyclic compound of formula in which Z is an atom with 3 or 4 valencies, R is absent or hydrogen, a hydroxyl group, an amino group or a hydrocarbon radical, {circle around (A)}, {circle around (B)} and {circle around (C)} are divalent radicals and are, independently of each other, a hydrocarbon chain optionally containing one or more heteroatoms and are optionally interrupted with a heteromacrocycle, wherein two of the radicals {circle around (A)}, {circle around (B)} and {circle around (C)} also comprise at least one molecular unit or consist essentially of a molecular unit having a triplet energy which is greater than that of the emission level of the complexed rare earth metal ion and which is substituted with an electron-donating group, and one of the radicals {circle around (A)}, {circle around (B)} and {circle around (C)} which does not comprise or does not consist essentially of the molecular unit having a triplet energy comprises only one pyridine radical which is substituted one or more times or unsubstituted, and measuring the fluorescent signal emitted in the assay.