Coated Capillary Electrophoresis Tubes and System

Abstract

The invention is directed to a capillary tube for electrophoresis that has a positively charged coating on the capillary inner surface that prevents positively charged analytes from adsorbing to the inner capillary surface. The capillary tube has an inner surface that is coated with a first polymer layer having a plurality of polymer groups comprising polyethylene imine, designated herein as (CH2CH2NH)X. The inner surface of the capillary typically has a second polymer layer covalently bonded to the first polymer layer. The invention includes a capillary tube where two or more than two polymer groups are covalently bonded to each other by a cross-linker. Also provided are an electrophoresis system the uses the coated capillary tubes, a method of performing electrophoresis that utilizes the coated capillary tubes, and a process for preparing the coated capillary tubes.

Description

CROSS-REFERENCES TO RELATED APPLICATIONS[0001]This application is a divisional of U.S. patent application Ser. No. 11 / 150,650, filed on Jun. 10, 2005, which in turn is a continuation of U.S. patent application Ser. No. 10 / 238,703, filed on Sep. 9, 2002, now U.S. Pat. No. 6,923,895, issued Aug. 2, 2005, the entire contents of all of which are hereby incorporated herein by reference.STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT[0002]Not applicableREFERENCE TO A “SEQUENCE LISTING,” A TABLE, OR A COMPUTER PROGRAM LISTING APPENDIX SUBMITTED ON A COMPACT DISK[0003]Not applicableBACKGROUND OF THE INVENTION[0004]The following description provides a summary of information relevant to the present invention and is not an indication that any of the information provided or publications referenced herein is prior art to the presently claimed invention.[0005]The electrokinetic separation of most analytes by electrophoresis is typically performed using ...

AI Technical Summary

Benefits of technology

[0008]The inner surface of the capillary typically further comprises a second polymer layer covalently bonded to the first polymer layer. As compared to a single layer, this additional layer results in a higher density of positive charges on the wall surface that facilitates an increase in sample flow through the capillary. The second polymer layer has a plurality of polymer groups comprising (CH2CH2NH)x attached by a second linker group to a second anchor group that is covalently bonded to a first anchor group of a polymer group from the first polymer layer. In this formula, “x” represents an integer independently selected for individual polymer groups within the first polymer layer or second polymer layer. The first polymer layer covalently bonded to the inner-surface of the capilla

Problems solved by technology

This is a problem because the adsorption of analytes continuously changes the surface properties of the capillary tube, resulting in changes in the electrosmotic flow velocity of the solution in the capillary.

This causes a fluctuation of migration time of analytes which results in inaccuracies and poor reproducibility.

This approach can reduce the adsorption of analytes to a limited extent, but results in a reduction in sample throughput through the capillary and consequently longer run times. Also, attempts have been made to cover the capillary inner surface with neutral coatings.

A problem with these coatings is that they are unstable under acidic and basic conditions.

None of the approaches used thus far have been ideal.

Images