Luminescence is the result of a chemical or biochemical reaction. Luminescence detection is simpler optically than fluorescence detection because luminescence does not require a light source for excitation or optics for selecting discrete excitation wavelengths. A typical luminescence optical system consists of a light-tight reading chamber and a PMT detector. Some plate readers offer filter wheel or tunable wavelength monochromator optical systems for selecting specific luminescent wavelengths.
Sample in the well before the chemical or biochemical reaction.
Reaction causes the sample to emit light that can be measured by a PMT detector
The ability to select multiple wavelengthsallows for detection of assays that contain multiple luminescent reporters, the development of new luminescence assays, as well as a means to optimize signal to noise. Luminescence reactions can be slow (glow) or fast (flash). Flash reactions typically require a rapid dispense and measure sequence on a well-by-well basis.
Common applications include luciferase -based gene expression assays, as well as cell viability, cytotoxicity, and biorhythm assays based on the luminescent detection of ATP.