Jack I Ohms

50097601, Apr 23, 1991

Dec 29, 1989

7/456594

Richard N. Zare - Stanford CA
Xiaohua Huang - Mountain View CA
Jack I. Ohms - Palo Alto CA

Board of Trustees of the Leland Stanford Junior University - Stanford CA

G01N 2726
B01D 5702

2041833

The electroosmotic velocity of an electrolyte is determined by displacing the electrolyte which fills a capillary tube by a second electrolyte which has the same composition as the first electrolyte but of a different concentration. The current flowing through the electrolyte is monitored until the current value becomes constant, indicating that all of the first electrolyte has been replaced by the second electrolyte. The time required for the first electrolyte to be entirely replaced by the second electrolyte is therefore measured to yield the electroosmotic velocity. Any components of samples in the electrolyte can also be detected by a detector to measure its actual velocity. Such actual velocity and the electroosmotic velocity of the electrolyte as a whole enables the electrophoretic mobility of the sample component to be determined. This method also enables the measurement of migration rates of micelles. If the constant current flowing when only the second electrolyte is in the tube is measured when the same voltage is applied as an additional data point, one need not wait until all of the first electrolyte has been replaced by the second electrolyte.

49975366, Mar 5, 1991

Jul 6, 1988

7/215834

Jack I. Ohms - Palo Alto CA
James C. Osborne - Sunnyvale CA

Beckman Instruments, Inc. - Fullerton CA

G01N 2726

2041801

Solid phases such as capillary tubes or solid supports used in chromatography, and in particular electrophoresis, are treated with oxidizing or reducing agents as needed to maintain or restore surface electrical charges or the lack thereof, which become modified during electrophoresis as a result of action by system components in the separation medium or the solutes themselves. The treatment is used as a means of achieving reproducible electroosmotic bulk flow when desired or suppressing unwanted electroosmotic flow arising due to the accumulation of charges on the surface. The result is improved reproducibility of retention times and component separation.

50193481, May 28, 1991

Jan 26, 1989

7/303004

Jack I. Ohms - Palo Alto CA
Majid Qadeer - Palo Alto CA
Harry A. Penhasi - Cupertino CA

Beckman Instruments, Inc. - Fullerton CA

G01N 3506

422 63

An automated chemical conversion unit for use in a peptide/protein sequencing process. The improved conversion methodology decreases the time necessary for the conversion reaction chemistry of the specific derivative of the sequenced amino acid to a more stable form. The conversion reaction is designed to be performed directly in a fraction collector tube which operates in one embodiment in conjunction with a thermoelectric temperature element to allow utilization of different temperature levels for different amino acid derivatives.