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:
Aug. 31, 1993
Filed:
Jul. 14, 1992
James E Young, La Honda, CA (US);
Jurgen A Lux, Niederkirchen, DE;
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
An electrophoresis system for controlling electroosmotic flow by affecting a zeta potential, wherein a conductive bridge provides continuity of control. A conductive coating on an optically transparent capillary tube is made of an opaque material which is removed at a detection window for on-column detection of sample constituents past the window. The conductive coating may be allowed to float relative to ground, may be grounded, or may be connected to one or more high voltage power supplies so that a potential gradient is established along the length of the conductive coating. A bridge establishes a low resistance electrical connection across the detection window, thereby establishing a continuity of external control of electroosmotic flow. In a first embodiment, the bridge is a generally flat metallic member that is adhesively bonded to the capillary tube at opposite ends of the detection window. The metallic member includes an aperture along the optical path from the on-column detector to the window. In a second embodiment the bridge is a wire that is bonded to the conductive coating at opposite ends of the window. A third embodiment is to leave a portion of the conductive coating along the length of the window at a region outside of the optical path. Another embodiment is one in which the detection window is at ground potential and the on-column detector itself is used to provide a bridge.