Patents by Inventor Barry L. Karger

Barry L. Karger has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6068749
    Abstract: A subatmospheric, variable pressure sample delivery chamber, useful as an electrospray ionization device for introducing a sample into a mass spectrometer or as a sample delivery device for delivery of a sample to a collection device at subatmospheric pressures, is disclosed. The sample delivery chamber is configured to maintain an operating pressure between 1 and 750 Torr, preferably between 50 and 700 Torr. The chamber has an inlet port for introduction of a gas and an exit port capable of being coupled either to a sampling orifice for an analytical device, usually a mass spectrometer, or directly to a pump for removal of gas. A sample delivery device extends from outside the chamber into the interior of the chamber.
    Type: Grant
    Filed: January 17, 1997
    Date of Patent: May 30, 2000
    Assignee: Northeastern University
    Inventors: Barry L. Karger, Frantisek Foret, Daniel P. Kirby
  • Patent number: 5872010
    Abstract: A microscale fluid handling system that permits the efficient transfer of nanoliter to picoliter quantities of a fluid sample from the spatially concentrated environment of a microfabricated chip to "off-chip" analytical or collection devices for further off-chip sample manipulation and analysis is disclosed. The fluid handling system is fabricated in the form of one or more channels, in any suitable format, provided in a microchip body or substrate of silica, polymer or other suitable non-conductive material, or of stainless steel, noble metal, silicon or other suitable conductive or semi-conductive material. The microchip fluid handling system includes one or more exit ports integral with the end of one or more of the channels for consecutive or simultaneous off-chip analysis or collection of the sample. The exit port or ports may be configured, for example, as an electrospray interface for transfer of a fluid sample to a mass spectrometer.
    Type: Grant
    Filed: July 3, 1996
    Date of Patent: February 16, 1999
    Assignee: Northeastern University
    Inventors: Barry L. Karger, Frantisek Foret, Paul M. Zavracky, E. Nicol McGruer, Qifeng Xue, Yuriy M. Dunayevskiy
  • Patent number: 5840388
    Abstract: A coated microcapillary column for high performance electrophoresis is disclosed. A preferred microcapillary includes a fused silica capillary column, the inner surface of the column having an interconnected polymeric coating of a polyvinyl alcohol (PVA) based polymer covalently attached to the column wall by Si--O--Si bonds. The resulting coated microcapillary column has good hydrolytic and pH stability and minimizes electroosmotic flow and interactions between sample components and the capillary wall. Also disclosed are a method of forming a polymeric coating layer for any surface by polymerizing the appropriate organic compounds in an organic solvent and a method of forming a column with a hydrophilic polymeric coating by directly converting an attached hydrophobic polymeric coating material to a hydrophilic polymeric coating material.
    Type: Grant
    Filed: May 22, 1997
    Date of Patent: November 24, 1998
    Assignee: Northeastern University
    Inventors: Barry L. Karger, Wolfgang Goetzinger
  • Patent number: 5783397
    Abstract: A method in which natural sample components are simultaneously fractionated and screened for compounds that bind tightly to specific molecules of interest is disclosed. Such newly isolated ligands are good candidates for potential therapeutic or diagnostic compounds. The natural sample is first combined with a potential target molecule and then subjected to capillary electrophoresis (CE). Charged (or even neutral) compounds present in the natural sample that bind to the added target molecule can alter its normal migration time upon CE, by changing its charge-to-mass ratio, or will cause a variation in peak shape or area. Complex formation can be detected by simply monitoring the migration of the target molecule during electrophoresis. Any new ligands that bind to the target molecule will be good candidates for therapeutic or diagnostic compounds. Interfering, weak-binding ligands commonly present in crude extracts are not detected.
    Type: Grant
    Filed: June 12, 1996
    Date of Patent: July 21, 1998
    Assignee: Northeastern University
    Inventors: Dallas E. Hughes, Barry L. Karger
  • Patent number: 5665216
    Abstract: A capillary column for high performance electrophoretic separation and detection of SDS proteins and system for using the same is disclosed. A preferred column includes a capillary, a static or dynamic layer of coating material on the inner surface of the capillary wall, and a hydrophilic polymer network which is UV-transparent in the tube, filling it. The capillary column is particularly useful in any electrophoresis system requiring UV-transparent materials.
    Type: Grant
    Filed: October 7, 1991
    Date of Patent: September 9, 1997
    Assignee: Northeastern University
    Inventors: Barry L. Karger, Katalin Ganzler, Aharon S. Cohen
  • Patent number: 5633129
    Abstract: The disclosure relates to a method for resolving double-stranded DNA species differing by at least one base pair. Each of the species is characterized by an iso-melting domain with a unique melting temperature contiguous with a melting domain of higher thermal stability.
    Type: Grant
    Filed: February 3, 1994
    Date of Patent: May 27, 1997
    Assignees: Massachusetts Institute of Technology, Northeastern University
    Inventors: Barry L. Karger, William G. Thilly, Frantisek Foret, Konstaintin Khrapko, Phouthone Koehavong, Aharon S. Cohen, Roger W. Giese
  • Patent number: 5571398
    Abstract: A capillary electrophoretic system and method for accurate and precise post-column manipulation of molecules separated by capillary electrophoresis is disclosed. The system of the invention includes a separation capillary; a detector positioned close to, and preferably less than approximately one cm from the outlet end of the capillary; and a sheath which surrounds and directs a collection buffer over the capillary outlet end. With the detector positioned as described, precise and accurate correlation is possible between detection of the separated components of a sample and their emergence from the capillary. The detector preferably includes optical fibers connected to a spectrophotometric detection method, such as UV detection or fluorescence, including laser induced fluorescence.
    Type: Grant
    Filed: December 23, 1994
    Date of Patent: November 5, 1996
    Assignee: Northeastern University
    Inventors: Barry L. Karger, Frantisek Foret, Odilo M uller
  • Patent number: 5370777
    Abstract: Disclosed herein are capillary columns for capillary electrophoretic analysis of sample constituents. In an embodiment, the columns comprise a bifunctional layer comprising a positively charged amine group adsorbed to the inner wall of the capillary and an active functional group; a gel composition; hydrophilic polymer; and a separation composition capable of being removed from the column, interspersed within the remainder of the column. The disclosed columns are particularly well suited for the analysis of surfactant: proteinaceous material complexes, nucleic acid sequence, and analysis of restriction fragments according to size.
    Type: Grant
    Filed: May 15, 1992
    Date of Patent: December 6, 1994
    Assignee: Beckman Instruments, Inc.
    Inventors: Andras Guttman, Chia-Hui Shieh, Barry L. Karger, Stephen J. Pentoney, Jr., Kenneth D. Konrad, Sushma Rampal, Katalin Ganzler
  • Patent number: 5348633
    Abstract: A method for quantitative detection of trace amounts of an analyte in a sample is disclosed. The method in the preferred embodiment includes providing an Fab' fragment of an immunoglobulin labelled at a reactive sulfhydryl group with a fluorescent dye; combining the labelled Fab' fragment with a sample that may contain the analyte; concentrating the elements of the resulting mixture in an electric field; separating the labelled analyte/agent complex formed from any unreacted labelled agent using capillary electrophoretic methods; and detecting the fluorescent signal of the labelled analyte/agent complex. The invention also is directed to a method of producing a labelled Fab' fragment that includes cleaving an immunoglobulin molecule to obtain one F(ab').sub.2 fragment; reducing the disulfide-bonds of the F(ab').sub.
    Type: Grant
    Filed: January 22, 1993
    Date of Patent: September 20, 1994
    Assignee: Northeastern University
    Inventors: Barry L. Karger, Kiyohito Shimura
  • Patent number: 5322608
    Abstract: A coated microcapillary column for high performance electrophoresis is disclosed. A preferred microcapillary includes a column; a universal sub-layer of coating material that has been highly crosslinked using a crosslinking agent and attached covalently or non-covalently to the column wall; and a variable top layer of a monomer or polymer, preferably crosslinked, attached to the sub-layer. The microcapillary preferably is prepared by covalently bonding a highly crosslinked siloxanediol sub-layer to the inner surface of the microcapillary wall and then causing a mixture of monomers or polymers to react in the bore of the microcapillary to form a top layer. The bilayer coating as used in a microcapillary prevents adsorption of solutes during electrophoresis and eliminates or controls electroosmotic flow. The disclosed coating may also be formed on other kinds of surfaces where similar surface modification is desired.
    Type: Grant
    Filed: December 23, 1992
    Date of Patent: June 21, 1994
    Assignee: Northeastern University
    Inventors: Barry L. Karger, Dieter Schmalzing, Frantisek Foret
  • Patent number: 5122248
    Abstract: Apparatus and method for conducting electrophoresis in a capillary tube under the influence of a pulsed electric field. Apparatus for separating and detecting molecular species of a sample in a conductive medium includes a capillary tube for containing conductive medium, means for introducing a sample into a conductive medium-filled capillary tube, means for applying a pulsed electric field across the conductive medium-filled capillary tube between its ends, and means for detecting constituent molecular species of a sample in a conductive medium-filled capillary tube as they traverse the tube. A method for separating and detecting molecular species of a sample in a conductive medium includes the steps of introducing the sample into a capillary tube filled with conductive medium, applying a pulsed electric field of up to 500 volts/centimeter between the ends of the capillary, and detecting the constituent molecular species of the sample as they traverse the capillary.
    Type: Grant
    Filed: May 18, 1990
    Date of Patent: June 16, 1992
    Assignee: Northeastern University
    Inventors: Barry L. Karger, Aharon S. Cohen, David N. Heiger
  • Patent number: 5112460
    Abstract: A microcapillary column for high performance electrophoresis. A preferred column includes a microcapillary, a thin layer of coating material covalently bonded to the inner surface of the microcapillary wall, and a gel comprising polyacrylamide polymerized in the tube, filling it. The gel-containing microcapillary is prepared by covalently bonding a layer of a suitable coating material to the inner surface of the microcapillary wall, and then causing a mixture of monomer with or without crosslinking agent, initiator, and polymerization catalyst to react in the bore of the microcapillary to form a polymeric matrix.
    Type: Grant
    Filed: October 13, 1989
    Date of Patent: May 12, 1992
    Assignee: Northeastern University
    Inventors: Barry L. Karger, Aharon S. Cohen
  • Patent number: 5089106
    Abstract: An improved, highly stable capillary column used in high performance capillary electrophoresis and method of preparing the same. The improved capillary column can significantly reduce the effects of electroosmosis during electrophoresis, is stable for reuse, and enables operation of the capillary column in high electric fields, resulting in high resolution separations in a minimum amount of time. The improved column comprises a capillary having a highly stable, coating matrix on the inner surface of the capillary wall. The highly stable coating matrix includes an intermediate layer hydrophobic phase chemically bonded to the inner wall of the capillary, a detergent which is physically adsorbed to the hydrophobic phase, and a polymerized monomer which is covalently bonded to the adsorbed detergent thereby forming a hydrophilic outer layer of the coating matrix.
    Type: Grant
    Filed: February 1, 1991
    Date of Patent: February 18, 1992
    Assignee: Northeastern University
    Inventors: Barry L. Karger, Roger W. Giese, Eva Szoko
  • Patent number: 5085757
    Abstract: An integrated temperature control/alignment system for use with a high performance capillary electrophoretic apparatus comprises a complementary pair of capillary column mounting plates formed from an electrically insulative, high thermal conductivity material for mounting a capillary column. The first mounting plate includes a well having a predetermined circumference, first and second grooves contiguous with the well and ports formed in the grooves and extending through the plate. The second mounting plate includes a plug configured for insertion in the well and ports aligned with the ports of the first mounting plate. Respective ends of the capillary column are seated and locked in the grooves to preposition the capillary column with respect to the ports.
    Type: Grant
    Filed: August 28, 1989
    Date of Patent: February 4, 1992
    Assignee: Northeastern University
    Inventors: Barry L. Karger, Robert J. Nelson
  • Patent number: 5084150
    Type: Grant
    Filed: August 14, 1990
    Date of Patent: January 28, 1992
    Assignee: Northeastern University
    Inventors: Barry L. Karger, Aharon Cohen
  • Patent number: 4997537
    Abstract: A microcapillary column for high performance electrophoresis. A preferred column includes a microcapillary, a thin layer of coating material covalently bonded to the inner surface of the microcapillary wall, a thin layer of a hydrophilic polymer absorbed on the layer of coating material, and a gel comprising polyacrylamide polymerized in the tube, filling it. The gel-containing microcapillary is prepared by covalently bonding a layer of a suitable coating material to the inner surface of the microcapillary wall, applying a layer of hydrophilic polymer, and then causing a mixture of monomer with or without crosslinking agent, initiator, and polymerization catalyst to react in the bore of the microcapillary to form a polymeric matrix.
    Type: Grant
    Filed: September 12, 1989
    Date of Patent: March 5, 1991
    Assignee: Northeastern University
    Inventors: Barry L. Karger, Aharon Cohen
  • Patent number: 4996343
    Abstract: Fast high resolution separations of biopolymers with retention of biological activity have been achieved by hydrophobic interaction chromatography using trialkoxy silyl ethers of the general formula(RO).sub.3 Si--(CH.sub.2).sub.m --O--(CH.sub.2 CH.sub.2 O).sub.n 13 (CH.sub.2).sub.p R'chemically bonded to silica-based chromatographic supports. In the formula R is alkyl of from one to five carbons, m is an integer from two to five, n is an integer from one to five, p is an integer from zero of ten, and R' is methyl, phenyl, or substituted phenyl. Stable and reproducible bonded phases are prepared in a novel solventless procedure by a bonding process which uses a defined and controlled amount of water on the silica surface and a gaseous or volatile basic catalyst such as ammonia to produce a controlled amount of silane polymerization and cross-linking in addition to extensive bonding between silane and silica.
    Type: Grant
    Filed: October 13, 1988
    Date of Patent: February 26, 1991
    Assignee: Northeastern University
    Inventors: Barry L. Karger, Binyamin Feibush, Neil T. Miller, Alvaro Figueroa
  • Patent number: 4940883
    Abstract: A window burner for creating windows by selective removal of polymer type coatings from capillary columns and very small diameter tubes. The burner includes an electric circuit which provides a predetermined, controlled current from a standard 120 or 220 volt AC outlet. The predetermined, controlled current electrically heats a resistive wire for a predetermined period of time. The resistive wire may have a predetermined configuration to facilitate mounting of the capillary column for selective burning. The size of the resistive wire and the predetermined period of time during which the predetermined, controlled current is provided thereto are factors determining the size of the window formed by selectively burning off the polymer coating.
    Type: Grant
    Filed: April 24, 1989
    Date of Patent: July 10, 1990
    Assignee: Northeastern University
    Inventors: Barry L. Karger, Robert J. Nelson
  • Patent number: 4898658
    Abstract: An integrated temperature control/alignment system for use with a high performance capillary electrophoretic apparatus is disclosed. In one exemplary embodiment the integrated temperature control/alignment system comprises a pair of capillary column mounting plates for mounting a capillary column as a constituent of the electrophoretic apparatus, a pair of secondary support plates, a pair of thermoelectric plates and external heat sink plates. Detection openings are formed in each of the plates as required so that a continuous detection path exists through the integrated temperature control/alignment system. The capillary column is seated and locked in grooves formed in the capillary column mounting plates so that the detection windows of the capillary column are coordinated with the aligned detection openings formed in the applicable plates of the integrated temperature control/alignment system.
    Type: Grant
    Filed: November 25, 1987
    Date of Patent: February 6, 1990
    Assignee: Northeastern University
    Inventors: Barry L. Karger, Aran Paulus, Aharon S. Cohen, Robert J. Nelson
  • Patent number: 4865707
    Abstract: An improved microcapillary column for high performance electrophoresis includes a microcapillary, a hydrophilic polymer within a gel of crosslinked polyacrylamide polymerized in the tube, and preferably, a thin layer of connecting material covalently bonded to the inner surface of the microcapillary wall and to the polymeric gel. The microcapillary is prepared by first covalently bonding a suitable bifunctional reagent to the inner surface of the microcapillary wall, and then causing a mixture of the hydrophilic polymer, monomer, crosslinking agent, and polymerization catalyst to react in the bore of the microcapillary to form a hydrophilic polymer-containing gel matrix which is covalently bonded to the microcapillary wall via the bifunctional reagent.
    Type: Grant
    Filed: January 12, 1988
    Date of Patent: September 12, 1989
    Assignee: Northeastern University
    Inventors: Barry L. Karger, Aharon S. Cohen