LUMINESCENCE ASSAYS

摘要

Disclosed are apparatus and method of detection of luminescence in which a luminescent species of interest is excited by a process of simultaneous or sequential absorption of at least two photons from at least one photon source, wherein the or each photon source is modulated at one or more frequencies, and luminescence measurements are made at a frequency or frequencies different from the or each modulation frequency, the or each frequency at which measurements are made being a function of the or each modulation frequency by virtue of the excitation process.