This invention relates to a method to correct for error in an anti-Stokes
photoluminescence measurement in a Foerster-type
resonance energy-transfer
assay. The method comprises the steps of exciting anti-Stokes photoluminescent molecules, ions, phosphors, chelates, or particles, i.e. donors of the
assay, with one
wavelength or multiple wavelengths of light wherein the
wavelength or wavelengths are greater than that of an emission
wavelength of
acceptor molecules in the
assay; measuring emission
light signal at a wavelength, which is the emission wavelength of the
acceptor molecules in the Foerster-type
resonance energy-transfer assay, and which differs from the emission wavelength of the anti-Stokes photoluminescent donor in at least two different
time windows; a first time window within the time window defined by the excitation light pulse, i.e. within the time
window opening when the excitation light pulse is switched on and closing when the excitation light pulse is switched off, and a second time window to follow the first time window not at all overlapping with the time window defined by the
excitation pulse; and correcting the emission
light signal measured, comprising signals originating from non-radiative and radiative
energy transfer, within the first time window by estimating the ratio of the signals from non-radiative and radiative
energy transfer or the
signal originating from radiative
energy transfer using at least one emission
light signal measured in the second time window. This invention also relates to the use of a device according to the method of the invention, a
system for carrying out the method and a
software product for the
system.