Fluorescent Lanthanide Chelates for Biological Systems

摘要

Certain lanthanide chelate complexes are known to emit strong fluorescence with very distinct physical properties that are different from those of organic fluorescent compounds: the fluorescence of lanthanide complexes is long-lived with the half decay-time of several hundreds microseconds to 2 ms. The complexes are excited by UV light and emit fluorescence in the visible region. The emission profile is very sharp and the wavelength is specific to each metal, for instance, Eu~(3+) complexes emit at 615 nm and Tb~(3+) at 545 nm regardless of the ligand. These properties show that the complexes can be excellent fluorescence labels for proteins and DNAs and, when time-resolved fluorometry is employed, provide highly sensitive detection methods in biotechnology. Among many labels we have developed, BHHCT-Eu~(3+) and BPTA-Tb~(3+) are suitable for immunoassay, DNA hybridization assay, and DNA chip technology. Homogeneous DNA hybridization assay systems using fluorescence resonance energy transfer and fluorescence intercalators will be introduced.