trFluor(TM) Eu-Cryptate succinimidyl ester

Many biological compounds present in cells, serum or other biological fluids are naturally fluorescent, and thus the use of conventional, prompt fluorophores leads to serious limitations in assay sensitivity due to the high background caused by the autofluorescence of the biological molecules to be assayed. The use of long-lived fluorophores combined with time-resolved detection (a delay between excitation and emission detection) minimizes prompt fluorescence interferences. Our trFluor(TM) Cryptate Eu succinimidyl ester has the highest stability with good water solubility. Compared to the other commercial Cryptate Eu probes, trFluor(TM) Cryptate Eu succinimidyl ester only has a single reactive group, eliminating the crosslinking possibility. These trFluor(TM) Eu probes have large Stokes shifts and extremely long emission half-lives when compared to more traditional fluorophores such as Alexa Fluor or cyanine dyes. Compared to the other TRF compounds, our trFluor(TM) Cryptate Eu probes have extremely high stability, high emission yield and ability to selectively label biomolecules. Moreover, our trFluor(TM) Eu probes are insensitive to fluorescence quenching when conjugated to biological polymers such as antibodies.