Core Technology & Physics
Emission
Getting the light back out–and the channel that is lost when energy leaves by another route.
Definition
Emission is the photon released as an excited fluorophoreLoading... returns to its ground state. It always carries less energy than the photon absorbed, so it appears at a longer wavelength–the Stokes shiftLoading..., which is what lets a filter separate signal from excitation light. Emission is not the only way out: in FRETLoading... the donor can transfer its energy to an acceptor without emitting at all, and the donor emission that goes missing is the measurement. Distinct from the emission filterLoading..., which is the hardware that selects it.