Beckman Instruments, Inc.

Other

The Penn State Research Foundation

Steven S Herrick

James C Sternberg

Andrew G Ewing

Mark A Hayes

Indu Kheterpal

Paul Tava

An electrophoretic separation apparatus includes a capillary tube having a length, a cross section, an inlet and an outlet. A first reservoir containing a solvent and, upon injection, a solute is in fluid-flow communication with the inlet and a second reservoir containing at least a solvent is also in fluid flow communication with the outlet, the capillary thereby being filled at least with the solvent. A first power supply means applies a separation potential between the first and second reservoirs and along the length of the capillary to thereby establish an electrophoretic flow of the solute therethrough. An electrically isolated plate is juxtaposed to an external surface of the capillary tube and is connected to a second power supply. An electrostatic field is thereby applied across the cross section of the capillary tube to control the electroosmotic flow therein. The electrical isolation of the plate prevents current flow between the power supply and the plate. The plate achieves effective electroosmotic flow control even though it extends only over a small portion of the length of the capillary tube.

Capillary electrophoresis apparatus with improved electroosmotic flow

The present invention provides processes for isoelectric focusing ('IEF') and associated detection, which incorporates a dynamic means of electroosmotic flow ('EOF') control during IEF and/or after IEF to effect solute mobilization. In accordance with the present invention, the EOF control during IEF and/or solute mobilization after IEF are accomplished by applying an external electric field, relative to an internal electric field, to modify the electroosmotic flow in the capillary. This can be done by disposing a conductive member at one or more locations outside and along the buffer column in the capillary. The conductive member may be statically charged or caused to conduct a current to create the external required electric field. The applied external electric field may be adjusted, relative to the internal electric field, during IEF as necessary to reduce or completely suppress EOF to prevent flow of the buffer. Upon the completion of IEF (irrespective of the method of reducing or removing EOF during IEF), the external electric field is adjusted, relative to the internal electric field, such that the buffer carrying the focused solutes is moved electroosmotically through the capillary past a detection point. The present invention is applicable to internally coated capillary which suppresses EOF even in the absence of the external electric field.

Methods and apparatus for separating and mobilizing solutes in a solute

Electronic calculator for automatically converting numerical data representative of a valve expressed in an initial one of a plurality of variably related units to numerical data representative of the same value expressed in any other one of said plurality of variably related units and for storing factors used in said conversions.

Conversion calculator

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Anaheim Hills, CA, United States of America

Steven S Herrick