Determination of Lanthanide Fluorescence Lifetime and Spectral Properties with Varioskan® Spectral Scanning Fluorometer

Abstract

Lanthanides are fluorochromes used in time-resolved fluorometry. An important characteristic of the lanthanide ions is their long fluorescent lifetime. It is defined as the time in which the initial fluorescence intensity of a fluorophore decays to 1/e. The lifetimes of the lanthanides are measured in microseconds.

When used as fluorochromes, the lanthanide ions are complexed with organic ligands. The structure of this chelate or cryptate has an effect on the fluorescent properties of the label. In this work the lifetime of some commercially used lanthanides were determined in different formats using a spectral scanning multimode reader. Additionally, excitation and emission spectra of the lanthanides were run to determine the optimal measurement parameters for each label in time-resolved measurement.

The results show that it is important to determine the parameters for the fluorohrome in the actual assay environment. It is possible to optimize the parameters of a time-resolved measurement easily with a spectral scanning instrument.