Patent ID: 8802424

Claim:
A system for analysis of fluorescent materials, comprising: a reaction region for containing a fluorescent reaction mixture; at least first and second excitation light sources; at least one detector; and an optical train for directing excitation light from the at least first and second excitation light sources to the reaction region and collecting fluorescent signals from the reaction region and directing the fluorescent signals to the detector, wherein the optical train comprises a beam modulation component that modulates the excitation light from the at least first and second excitation light sources, the optical train is configured to provide at least first and second modulated beams of excitation light to the reaction region at different times, the optical beam modulation component is configured to modulate the excitation light at a frequency of between about 20 Hz and about 1000 Hz, and the detector is configured to detect each type of the fluorescent signals corresponding to each of the at least first and second modulated beams of the excitation light at different times, wherein the detector is synchronized with the at least first and second modulated beams of excitation light to have a sampling rate that is greater than the frequency of modulation of the at least first and second modulated beams, thus substantially reducing the background noise from reflected excitation lights and autofluorescence.