Patent ID: 8389291

Claim:
A method for measuring fluorescence emissions from a particle in a flow cytometer, comprising the steps of: (a) providing a first excitation light source; (b) modulating said first excitation light source with a first modulation signal at a first frequency to produce a first modulated excitation beam; (c) providing a second excitation light source; (d) modulating said second excitation light source with a second modulation signal at a second frequency to produce a second modulated excitation beam, said second frequency being different than said first frequency; (e) combining said first and second modulated excitation beams to produce a combined modulated excitation beam; (f) shining said combined modulated excitation beam on a particle; (g) detecting fluorescent emission from said particle; and (h) determining, without access to the first or second modulation signals, a first portion of said detected fluorescent emission caused by excitation of said particle by said first modulated excitation beam and a second portion of said detected fluorescent emission caused by excitation of said particle by said second modulated excitation beam.