摘要 |
A capillary electrophoretic system and method for accurate and precise post-column manipulation of molecules separated by capillary electrophoresis is disclosed. The system of the invention includes a separation capillary; a detector positioned close to, and preferably less than approximately one cm from the outlet end of the capillary; and a sheath which surrounds and directs a collection buffer over the capillary outlet end. With the detector positioned as described, precise and accurate correlation is possible between detection of the separated components of a sample and their emergence from the capillary. The detector preferably includes optical fibers connected to a spectrophotometric detection method, such as UV detection or fluorescence, including laser induced fluorescence. The sheath collection buffer, the capillary and an electrophoresis buffer reservoir, for supplying buffer to the inlet end of the capillary, are in electrical contact in an electrical circuit and provide the electric field required for separation of a sample of molecules. The separated components of the sample are mixed with collection buffer as they emerge from the outlet end of the capillary. They are then collected into or on any collection device, such as vials, collection capillaries or membranes, or they are transferred to other devices for further analysis, such as mass spectroscopy.
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