Leland Stanford Junior University

Jason B Shear

Richard Neil Zare

Harvey Abraham Fishman

Luis A Colon

Rajeev Dadoo

Jonathan V Sweedler

Neil Shafer

In many separation techniques, such as field flow fractionation, liquid chromatography and electro-phoresis, chemical species form bands that migrate at different velocities. If the data-digitization rate and excitation intensity are both set to be optimal for the fastest migrating band, to compensate for different band velocities, both the data-digitization rate and the excitation intensity are decreased as a function of time by a factor equal to the migration time of the fastest migrating band to the separation time.

System for sample detection with compensation for difference in

An on-column derivatization scheme where a liquid or solid labeling reagent is provided in a capillary to react chemically with a sample in order to label the sample. Electrophoretic separation may be carried out immediately thereafter to simplify the derivatization, separation and detection process. By localizing the labeling process to a small area within the capillary, fast kinetics and high reaction yield are achieved.

On-column derivatization in capillary electrophoresis

An electrophoretic or chromatographic separation capillary containing a fluid defines a bore therein through which a sample travels and separates into components. The tube has a side wall defining a through hole therein which is surrounded by a medium including a substance. The substance is introduced into the capillary through the hole by means of gravity, pressure or electroosmosis. The substance introduced may be used to label sample components to enhance detection, or to enhance separation of sample components.

On-column junction for capillary columns

This invention relates to a detection method and apparatus useful in capillary electrophoresis and capillary chromatography that employs an array of solid state detector such as a charge-coupled device operating in the time-delayed integration mode which allows more exposure time of the moving analyte zones. The CCD is synchronized so that after a normal exposure of the CCD, the charge information in every row of the CCD is shifted toward one end of the CCD and the charge/signal information in the last row is quantified. Applying the CCD and the time-delayed integration method in effect increases the effective sampling volume of the flow cell without introducing band broadening. Use of the CCD as a fluorescence detection in capillary electrophoresis separations allows analytes to be differentiated both in migration time and fluorescence emission, yielding detection limits for fluorophores in the 1-8.times.10.sup.-20 mole range.

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Menlo Park, CA, United States of America

Jason B Shear