citation入=340nm 1000 cycles/s 400 Boo 1000 Delay time Counting time Time (us) By using TRF technology background signal (red) can be separated from the Eu-signal (green Excitation Emission 203 10 4o0 50O 600 Wavelength (nm) Clear separation of excitation and emission spectra (a large Stokes shift) is an important feature of lanthanide cheta fluorophores