The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 19, 1993
Filed:
Sep. 04, 1991
James E Young, La Honda, CA (US);
Douglass McManigill, Palo Alto, CA (US);
Jurgen A Lux, Palo Alto, CA (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
A system and method for controlling the rate of electroosmotic flow in capillary electrophoresis. A first high voltage power supply is electrically connected to the inlet end of a capillary tube, while a second high voltage power supply is connected at an outlet end. The potential difference across the capillary tube is therefore the difference between the high voltages. Electroosmotic flow can be controlled by varying the two high voltages correspondingly to maintain the same potential difference but to achieve a different voltage offset relative to ground. Optionally, the voltage offset may be varied during electrophoresis analysis to slow migration during periods in which constituents are closely spaced and to speed migration when constituents are sufficiently spaced apart. A conductive capillary tube coating which is preferably grounded defines an external control area for electroosmotic flow. A detector is located downstream of the external control area, so that the coating is a unitary layer.