Leland Stanford Junior University

Jonathan V Sweedler

Richard Neil Zare

Jason B Shear

Harvey Abraham Fishman

Luis A Colon

Takao Tsuda

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

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.

Method and device employing time-delayed integration for detecting

An elongated or rectangular cross-section capillary is disclosed for use in capillary electrophoresis using optical detection. With rectangular capillaries, heat is efficiently dissipated which permits large volume applications in capillary electrophoresis. In addition, the increase in cell pathlength produces significant improvements in absorbance detection sensitivity. This advantage is also important for laser-induced fluorescence, optical rotation, and other pathlength-dependent detection schemes. Because flat walls produce less optical distortion than circular capillary walls, rectangular capillaries are particularly useful when parameters such as refractive index, photodeflection, direct visualization or particle counting are used for detection. Capillary electrophoresis employing rectangular capillaries allows for two-dimensional separations.

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Redwood City, CA, United States of America

Jonathan V Sweedler