SINGLE MOLECULE IDENTIFICATION USING SELECTED FLUORESCENCE CHARACTERISTICS

摘要

Single fluorescent molecules in a flowing sample stream (14) are distinguished and identified using only a single laser excitation wavelength (38). A sample stream (14) is formed containing a dilute mixture of single molecule fluorophores (12), wherein each one of the fluorophores is serially ordered in the sample stream (14). The sample stream (14) is illuminated with a single excitation wavelength laser (38) effective to excite each fluorophore one at a time. Fluorescence emission photons from each said fluorophore are detected (48). A burst size is determined for each fluorophore to identify each fluorophore. A pulsed laser may be used (38), where burst size and an intra-burst fluorescence decay rate for each fluorophore are determined simultaneously from the detected fluorescence emission photons. The burst size and the decay rate are correlated to identify each fluorophore.