METHOD AND APPARATUS FOR SINGLE MOLECULE TWO COLOR FLUORESCENT DETECTION AND MOLECULAR WEIGHT AND CONCENTRATION DETERMINATION

摘要

The present invention comprises a novel method for detecting the presence of a target molecule in a sample and determining its molecular weight and concentration. The method involves the determination of electrokinetic velocities by measuring the time required for individual molecules labeled with at least two fluorescent probes to travel a fixed distance between two laser beams. Comparison of the electrophoretic velocity known to be characteristic of particular molecular weight standards with that of the target species permits determination of the molecular weight of the target. Alternatively, a two probe single detection zone method utilizing mechanical, electroosmotic or electrokinetic flow of a sample through a transport tube permits the identification of a target molecule in a complex test sample. The method is extremely sensitive, allowing one to detect and determine in a matter of seconds the molecular weight of a target molecule present in a concentration as small as one femtomolar.