METHOD AND APPARATUS FOR DETECTING FLUORESCENCE EMITTED BY PARTICLE-BOUND FLUOROPHORES CONFINED BY PARTICLE TRAPS

摘要

A method of detecting a fluorescence signal emitted by fluorophores bound to particles confined in a particle trap, includes an objective lens having a focal plane, which is normally the focal plane for incident collimated light. The particle trap is typically located in the focal plane, and a beam of excitation light is directed via the objective lens onto the confined particles in the trap. The excitation light is in the form of a divergent beam coming to focus at a plane displaced from the focal plane. The divergent beam has a spot diameter at the focal plane determined by the divergence of the beam. The fluorescent light emitted by the fluorophores is detected with a confocal detector.