With Adjustment Or Alteration Of Electro-osmotic Bulk Flow Patents (Class 204/454)
  • Patent number: 7439075
    Abstract: A method of discharging a fluid flow with suspended microparticles from a fluidic microsystem (10) is described, whereby the fluid flow converges with at least one output flow to form a discharge flow at the end of a discharge channel (14) of the microsystem, and the discharge flow is delivered through a conduction element (19). A microsystem with a flow output device for implementation of this method is also described.
    Type: Grant
    Filed: February 8, 2001
    Date of Patent: October 21, 2008
    Assignee: Perkinelmer Cellular Technologies Germany GmbH
    Inventors: Gunter Fuhr, Stephen Graham Shirley, Torsten Muller, Thomas Schnelle, Rolf Hagedorn
  • Patent number: 7431888
    Abstract: A microfluidic device preferably made of a thermoplastic polymer that includes a channel or a multiplicity of channels whose surfaces are modified by photografting. The device further includes a porous polymer monolith prepared via UV initiated polymerization within the channel, and functionalization of the pore surface of the monolith using photografting. Processes for making such surface modifications of thermoplastic polymers and porous polymer monoliths are set forth.
    Type: Grant
    Filed: September 19, 2003
    Date of Patent: October 7, 2008
    Assignee: The Regents of the University of California
    Inventors: Jean M. J. Frechet, Frantisek Svec, Thomas Rohr
  • Publication number: 20080128279
    Abstract: A microfabricated device employing a bridging membrane and methods for electrokinetic transport of a liquid phase biological or chemical material using the same are described. The bridging membrane is deployed in or adjacent to a microchannel and permits either ionic current flow or the transport of gas species, while inhibiting the bulk flow of material. The use of bridging membranes in accordance with this invention is applicable to a variety of processes, including electrokinetically induced pressure flow in a region of a microehannel that is not influenced by an electric field, sample concentration enhancement and injection, as well as improving the analysis of materials where it is desired to eliminate electrophoretic bias. Other applications of the bridging membranes according to this invention include the separation of species from a sample material, valving of fluids in a microchannel network, mixing of different materials in a microchannel, and the pumping of fluids.
    Type: Application
    Filed: October 19, 2007
    Publication date: June 5, 2008
    Inventors: Stephen C. Jacobson, J. Michael Ramsey, Christopher T. Culbertson, William B. Whitten, Robert S. Foote
  • Patent number: 7316543
    Abstract: An electroosmotic micropump having a plurality of thin, closely-spaced, approximately planar, transversel aligned partitions formed in or on a substrate, among which electroosmotic flow (EOF) is generated. Electrodes are located within enclosed inlet and outlet manifolds on either side of the partition array. Inlet and outlet ports enable fluid to be pumped into and through the micropump and through an external friction load or head. Insulating layer coatings on the formed substrate limit substrate leakage current during pumping operation.
    Type: Grant
    Filed: May 30, 2003
    Date of Patent: January 8, 2008
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventors: Kenneth E. Goodson, Thomas W. Kenny, Juan G. Santiago, Daniel J. Laser, Chuan-Hua Chen
  • Patent number: 7285421
    Abstract: An apparatus and method for capillary zone electrophoresis includes a polyelectrolyte multilayer positioned in a capillary tube for analytical separations of macromolecules. The capillary comprises a passage defined by passage walls comprising fused silica. The polyelectrolyte multilayer is positioned within the passage adjacent the walls, and comprises an organic polyelectrolyte. The passage may further comprise nonporous silica particles coated with a multilayer including a plurality of polyelectrolyte layers. An apparatus includes a power supply having a positive electrode and a negative electrode for generating an electric field therebetween. The apparatus includes a capillary having a passage formed by passage walls and comprising therein a polyelectrolyte multilayer positioned substantially within the passage.
    Type: Grant
    Filed: September 2, 2004
    Date of Patent: October 23, 2007
    Assignee: Florida State University Research Foundation, Inc.
    Inventors: Joseph B. Schlenoff, Timothy W. Graul
  • Patent number: 7282127
    Abstract: A microcapillary device includes a microcapillary tube. An anode is positioned at a first end of the microcapillary tube. A cathode is positioned at a second end of said microcapillary tube. A plurality of electric field reducing components are spaced apart along a length of the microcapillary tube. The anode and the cathode generate an electric field along the length of the microcapillary tube, and the plurality of electric field reducing components selectively reduce the electric field at spatial intervals along the length of the microcapillary tube.
    Type: Grant
    Filed: April 7, 2005
    Date of Patent: October 16, 2007
    Assignee: East Carolina
    Inventor: Martin Bier
  • Patent number: 7252928
    Abstract: Methods for reducing surface adsorption of biological materials to the walls of microfluidic conduits in microscale devices are provided. In an example of the methods, one or more colloidal-size particles, such as colloidal silica particles, are flowed in a fluid within the microfluidic conduit in the presence of one or more adherent biological materials (such as one or more proteins, cells, carbohydrates, nucleic acids, lipids and the like) to adsorb to the materials and prevent them from binding to the capillary walls of the microfluidic conduit. Other adsorption inhibition agents such as detergents and nonaqueous solvents can be used alone or in combination with colloidal particles to reduce surface adsorption in microfluidic conduits.
    Type: Grant
    Filed: February 25, 2003
    Date of Patent: August 7, 2007
    Assignee: Caliper Life Sciences, Inc.
    Inventors: Dean G. Hafeman, Aileen Zhou
  • Patent number: 7243670
    Abstract: A microfluidic system, particularly a microfluidic chip, with at least one operational channel, in which a fluid and/or the constituents contained therein are moveable in the direction of the operational channel by a driving force, particularly by using pressure, acoustic energy, or an electrical and/or a magnetic field. At least one measurement sensor used to measure a measurable value assigned to the fluid and derivable in the region of the fluid and at least one regulator is provided to regulate the driving force and/or a parameter that may be influenced by it, wherein the regulator is coupled with a measurement sensor and a device used to alter the driving force and/or the parameter that may be influenced by it. The microfluidic system further relates to a procedure to transport and guide a fluid and/or the constituents contained therein within a microfluidic system of the type described above.
    Type: Grant
    Filed: June 24, 2002
    Date of Patent: July 17, 2007
    Assignee: Agilent Technologies, Inc.
    Inventors: Klaus Witt, Monika Dittmann, Friedrich Bek
  • Patent number: 7201834
    Abstract: Methods and compositions for modifying the surface of a polymeric substrate are provided. In the subject methods, at least a portion of the surface of the polymeric substrate is contacted with a biofouling resistant surfactant composition. At least a portion of the surfactant molecules of the composition are end modified with a non-reactive, charged end group that is charge stable over a pH range of about 2 to 12. The subject methods and compositions find particular use with electrophoretic devices, such as capillary electrophoretic devices.
    Type: Grant
    Filed: March 11, 2003
    Date of Patent: April 10, 2007
    Assignee: Agilent Technologies, Inc.
    Inventors: Sally A. Swedberg, Karla M. Robotti, Karin Caldwell
  • Patent number: 7081190
    Abstract: The present invention provides methods of electrophoretically separating macromolecular species, as well as compositions and systems useful in carrying out such methods. Specifically, the methods of the present invention comprise providing a substrate that has at least a first capillary channel disposed therein. The surface of the channel has a first surface charge associated therewith, and is filled with a water soluble surface adsorbing polymer solution that bears a net charge that is the same as the charge on the capillary surface.
    Type: Grant
    Filed: May 24, 2002
    Date of Patent: July 25, 2006
    Assignee: Caliper Life Sciences, Inc.
    Inventor: Robert S. Dubrow
  • Patent number: 7070681
    Abstract: A novel electrokinetic instability (EKI) micromixer and method takes advantage of the EKI to effect active rapid stirring of confluent microstreams of biomolecules without moving parts or complex microfabrication processes. The EKI is induced using an alternating current (A/C) electric field. Within seconds, the randomly fluctuating, three-dimensional velocity field created by the EKI rapidly and effectively stirs an initially heterogeneous solution and generates a homogeneous solution that is useful in a variety of biochemical and bioanalytical systems. Microfabricated on a glass substrate, the inventive EKI micromixer can be easily and advantageously integrated in molecular diagnostics apparatuses and systems, such as a chip-based “Lab-on-a-Chip” microfluidic device.
    Type: Grant
    Filed: January 24, 2002
    Date of Patent: July 4, 2006
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventors: Juan G. Santiago, Michael H. Oddy, James C. Mikkelsen, Jr.
  • Patent number: 7060170
    Abstract: In accordance with the present invention, stable electroosmotic flow systems and methods for designing the same are disclosed. The invention provides electroosmotic flow systems comprising electroosmotic flow elements, including bridge elements, that have matching flux ratios, i.e., when two or more elements of an electroosmotic flow system are in fluidic and electrical communication at a junction, the flux ratio for each of the elements is selected so that the difference in flux ratios of any two elements is less than a target value. The invention also provides methods for designing such systems. Also disclosed is a novel design for the terminal portions of electroosmotic flow (EOF) and bridge elements and for junctions in electroosmotic flow systems, whereby the elements are designed so that the terminal current flux is much smaller than the element current flux.
    Type: Grant
    Filed: May 1, 2002
    Date of Patent: June 13, 2006
    Assignee: Eksigent Technologies LLC
    Inventors: Phillip H. Paul, David W. Neyer
  • Patent number: 7060171
    Abstract: Methods and systems of monitoring reactions, e.g., assays, that filter out background signal from substrate, in detecting the product. The methods and systems controllably move detectable reaction product from a first location to a second location at which the product is detected while controllably moving potentially interfering substrate materials away from or not toward the second location. Controllable movement of the different species is accomplished through the controlled combination of bulk fluid flow and differential electrophoresis of substrate and product to move the product, but not the substrate past the detection region.
    Type: Grant
    Filed: July 24, 2002
    Date of Patent: June 13, 2006
    Assignee: Caliper Life Sciences, Inc.
    Inventors: Theo T. Nikiforov, Aileen Zhou
  • Patent number: 7052589
    Abstract: Method and materials to carry out preparative-scale electrophoretic separations based on the principle of dynamically created non-co-directional effective electrophoretic mobilities are disclosed. The primary application areas of the method are in the separation, purification, enrichment, concentration or conditioning of both small and large molecular weight, weak and strong electrolyte compounds, such as pharmaceuticals, oligo- and polypeptides, proteins, oligonucleotides, etc. These objectives can be achieved based on the use of a secondary chemical equilibrium, alone or in combination with multiple protic and other secondary chemical equilibria. Though such electrophoretic operations could be achieved by other means, such as by conventional zone electrophoresis or isotachophoresis, the method disclosed here can provide greater separation power, simplicity and higher production rates.
    Type: Grant
    Filed: March 18, 2002
    Date of Patent: May 30, 2006
    Assignee: The Texas A&M University System
    Inventor: Gyula Vigh
  • Patent number: 7037416
    Abstract: Microfluidic methods, devices, and systems are provided for monitoring and controlling flow rates in response to one or more marker signals. The marker signals are used to provide an indication of flow rate in the various channels of the devices. Signals obtained from the markers are deconvoluted and used in a feedback loop to make flow rate adjustments.
    Type: Grant
    Filed: January 11, 2001
    Date of Patent: May 2, 2006
    Assignee: Caliper Life Sciences, Inc.
    Inventors: J. Wallace Parce, Claudia B. Jaffe
  • Patent number: 7018520
    Abstract: Methods and devices are described for concentration and cleanup of samples containing bio-molecule analytes (e.g., polynucleotides, such as DNA, RNA, PNA). Various embodiments provide for pH-mediated sample concentration and cleanup of nucleic acid samples with channel devices (e.g., cross-T format, microchannel devices).
    Type: Grant
    Filed: September 9, 2002
    Date of Patent: March 28, 2006
    Assignee: Applera Corporation
    Inventor: Karl O. Voss
  • Patent number: 7011970
    Abstract: This new automatic bio-manipulation factory system for manipulating a single cell comprises: a bio-MEMS that transports, separates, and extracts a single cell for manipulation from a plurality of cells, controls the rotation-orientation of the extracted cell automatically, and enables the extracted cell to maintain a certain temperature; and a micro manipulation system that obtains vision information and manipulation information about the extracted single cell and the manipulation tool, provides such information to operator, manipulates the extracted single cell by transmitting the rotation-orientation feedback information and the cell manipulation order of the operator to the bio-MEMS, and manipulates the manipulation tool by transmitting the tool manipulation order of the operator to the manipulation tool. The conventional manual and individualized single cell manipulation can be automated and processed collectively by systematically combining the bio-MEMS with the micro manipulation system.
    Type: Grant
    Filed: March 25, 2003
    Date of Patent: March 14, 2006
    Assignee: Korean Institution of Science and Technology
    Inventors: Byung-Kyu Kim, Jung-Yul Park, Deok-Ho Kim, Jong-Oh Park
  • Patent number: 6982028
    Abstract: A method is described for modifying performed channels fabricated in a variety of substrate materials including PMMA. The method involves exposing a portion of a fluid flow channel to light at a fluence and wavelength which modifies the surface charge of the substrate at the exposure site. The method can be used to modulate electroosmotic flow in channels or to immobilize chemical compounds or biological species in the fluid flow channels at the modified surfaces.
    Type: Grant
    Filed: July 13, 2001
    Date of Patent: January 3, 2006
    Assignee: The United States of America as represented by the Secretary of Commerce
    Inventors: Timothy J. Johnson, Emanuel A. Waddell, Jr., David J. Ross, Laurie E. Locascio
  • Patent number: 6960285
    Abstract: An electrokinetic pump capable of producing high pressure is combined with a nozzle having a submicron orifice to provide a high pressure spray device. Because of its small size, the device can be contained within medical devices such as an endoscope for delivering biological materials such as DNA, chemo therapeutic agents, or vaccines to tissues and cells.
    Type: Grant
    Filed: September 30, 2002
    Date of Patent: November 1, 2005
    Assignee: Sandia Naitonal Laboratories
    Inventors: Joseph S. Schoeniger, Phillip H. Paul, Luke Schoeniger
  • Patent number: 6939451
    Abstract: A microfluidic device having integrated components for conducting chemical operations. Depending upon the desired application, the components include electrodes for manipulating charged entities, heaters, electrochemical detectors, sensors for temperature, pH, fluid flow, and other useful components. The device may be fabricated from a plastic substrate such as, for example, a substantially saturated norbornene based polymer. The components are integrated into the device by adhering an electrically conductive film to the substrate. The film may be made of metal or an electrically conducting ink and is applied to the device through metal deposition, printing, or other methods for applying films. Methods for reducing bubble formation during electrokinetic separation and methods for heating material in a microfluidic device are also disclosed.
    Type: Grant
    Filed: August 24, 2001
    Date of Patent: September 6, 2005
    Assignee: Aclara Biosciences, Inc.
    Inventors: Mingqi Zhao, Petr Vanysek, Antonio Ricco, Hilary S. Lackritz, Zhu Qun, Uyen Nguyen, Torleif O. Bjornson
  • Patent number: 6923895
    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.
    Type: Grant
    Filed: September 9, 2002
    Date of Patent: August 2, 2005
    Assignee: Beckman Coulter, Inc.
    Inventors: Chitra K. Ratnayake, Isabel C. Flores
  • Patent number: 6902657
    Abstract: A low molecular weight non-entangled polyvinylpyrrolidone for use as a separation media for microchannel electrophoretic separation. The separation media may be used in a system in which multiple samples of small compounds are injected into a single microchannel at time spaced intervals followed by a continuous detection interval.
    Type: Grant
    Filed: June 15, 2001
    Date of Patent: June 7, 2005
    Assignee: Amersham Biosciences Corp.
    Inventors: Marek Minarik, Melanie M. Mahtani
  • Patent number: 6890411
    Abstract: The present invention generally relates to methods and devices for the control of the movement of fluids and electrically charged sample components within those fluids. More particularly, the present invention permits exclusion or concentration of specifically chosen sample components within a fluid. The present invention provides an analytical device, either microchip- or capillary-based, having the means to exclude specific sample components of interest from a capillary or channel for the purpose of preconcentration or control of movement of sample components. Such a control system includes a means for controlling the flow of the fluid in the channel and the placement of an electrode at the immediate entrance of each channel on such devices so that material may be directly manipulated by effects of both bulk flow and electrically driven migration.
    Type: Grant
    Filed: June 29, 1999
    Date of Patent: May 10, 2005
    Assignee: Arizona Board of Regents
    Inventors: Mark A. Hayes, Nolan A. Polson
  • Patent number: 6863790
    Abstract: A simple and rugged sheathless interface for capillary electrophoresis/electrospray ionization-mass spectrometry (CE/ESI-MS) was designed using common laboratory tools and chemicals. The interface uses a small platinum (Pt) wire which is inserted into the CE capillary through a small hole near the terminus. The position of the wire inside the CE capillary and within the buffer solution is analogous to standard CE separation operations where the terminus of the CE capillary is placed inside a buffer reservoir along with a grounded platinum electrode. By combining the use of the in-capillary electrode interface with sharpening of the fused silica tip of the CE capillary outlet, a stable electrospray current was maintained for an extended period of time. The design was successfully applied to CE/ESI-MS separations and analysis of mixtures of peptides and proteins. A detection limit of approximately 4 femtomole (S/N=3) was achieved for detection of myoglobin utilizing a 75 ?m-i.d.
    Type: Grant
    Filed: August 5, 1999
    Date of Patent: March 8, 2005
    Assignee: Board of Regents University of Texas System
    Inventors: Mehdi Moini, Ping Cao
  • Patent number: 6841054
    Abstract: An apparatus and method for capillary zone electrophoresis includes a polyelectrolyte multilayer positioned in a capillary tube for analytical separations of macromolecules. The capillary comprises a passage defined by passage walls comprising fused silica. The polyelectrolyte multilayer is positioned within the passage adjacent the walls, and comprises an organic polyelectrolyte. The passage may further comprise nonporous silica particles coated with a multilayer including a plurality of polyelectrolyte layers. An apparatus includes a power supply having a positive electrode and a negative electrode for generating an electric field therebetween. The apparatus includes a capillary having a passage formed by passage walls and comprising therein a polyelectrolyte multilayer positioned substantially within the passage.
    Type: Grant
    Filed: May 14, 2002
    Date of Patent: January 11, 2005
    Assignee: Florida State University Research Foundation, Inc.
    Inventors: Joseph B. Schlenoff, Timothy W. Graul
  • Patent number: 6805783
    Abstract: A device and method for pumping an electrolyte solution includes a conduit having a first end, a second end and a lumen for containing the electrolyte solution. An opening at each end of the conduit allows electrolyte solution to enter and exit the lumen of the conduit. The device further includes a ferroelectric member that is positioned along a portion of the conduit. The ferroelectric member is formed with a contact surface for interaction with the electrolyte solution. An electrode is positioned adjacent to the ferroelectric member to polarize the ferroelectric member and charge the contact surface. Driving electrodes are positioned to establish a potential difference in the electrolyte solution across the portion of the conduit containing the ferroelectric member.
    Type: Grant
    Filed: December 13, 2000
    Date of Patent: October 19, 2004
    Assignee: Toyo Technologies, Inc.
    Inventor: Tihiro Ohkawa
  • Publication number: 20040173459
    Abstract: A method for improving the pumping performance of an electrokinetic pump. The addition of zwitterions to the pump fluid or electrolyte of an electrokinetic pump (EKP) has been found to improve the pumping performance by increasing the maximum pressure and flow rate generated and increasing the efficiency for a given applied voltage. Zwitterions comprise a class of molecules that contain separated positive and negative charge centers within the molecule, are substantially electrically neutral, and generally exhibit a large inherent dipole moment (≈20−25 D) as a consequence of charge separation within the structure of the molecule. The addition of the zwitterion trimethyl ammonium propane sulfonate to an EKP electrolyte has resulted in a 3-fold increase in pump efficiency and a 2.5-fold increase in generated pressure for a given applied voltage.
    Type: Application
    Filed: March 12, 2004
    Publication date: September 9, 2004
    Inventor: Brian J. Kirby
  • Patent number: 6787015
    Abstract: Capillary electrophoresis is performed under conventional conditions in microchannels having a norbornene based polymer surface. The norbornene based polymers can be used as a solid substrate for forming the necessary features for a microfluidic device, where the entire device may be made of norbornene based polymer. Conveniently, a norbornene based polymer layer having a lower glass transition temperature may be used to adhere a cover or enclosing layer to the substrate to enclose the microchannels and provide a bottom for the reservoirs.
    Type: Grant
    Filed: July 20, 2001
    Date of Patent: September 7, 2004
    Assignee: Aclara Biosciences, Inc.
    Inventors: Hilary Lackritz, Ingrid Cruzado, Hongdong Tan
  • Publication number: 20040168918
    Abstract: The invention provides compositions, methods and kits for high speed, high resolution of analytes by capillary electrophoresis starting with uncoated capillaries. The compositions comprise a sieving component, comprising a non-crosslinked acrylamide polymer, and a surface interaction component, comprising at least one uncharged and non-crosslinked water-soluble silica-adsorbing polymer. Methods for employing the novel compositions in capillary electrophoresis are provided. Kits comprising the novel compositions for use in the novel methods are also provided.
    Type: Application
    Filed: March 5, 2004
    Publication date: September 2, 2004
    Applicant: Applera Corporation
    Inventors: Karl O. Voss, Aldrich N.K. Lau
  • Publication number: 20040163960
    Abstract: A separation matrix for capillary electrophoresis of single-stranded nucleic acids is disclosed. The matrix comprises an aqueous buffer containing a denaturant and (hydroxypropyl)methyl cellulose.
    Type: Application
    Filed: February 21, 2003
    Publication date: August 26, 2004
    Inventor: Wei Wei
  • Patent number: 6770182
    Abstract: The present invention improves the performance of microchannel systems for chemical and biological synthesis and analysis by providing a method and apparatus for producing a thin band of a species sample. Thin sample bands improve the resolution of microchannel separation processes, as well as many other processes requiring precise control of sample size and volume. The new method comprises a series of steps in which a species sample is manipulated by controlled transport through a junction formed at the intersection of four or more channels. A sample is first inserted into the end of one of these channels in the vicinity of the junction. Next, this sample is thinned by transport across the junction one or more times. During these thinning steps, flow enters the junction through one of the channels and exists through those remaining, providing a divergent flow field that progressively stretches and thins the band with each traverse of the junction.
    Type: Grant
    Filed: November 14, 2000
    Date of Patent: August 3, 2004
    Assignee: Sandia National Laboratories
    Inventors: Stewart K. Griffiths, Robert H. Nilson
  • Publication number: 20040140210
    Abstract: Provided is a method for determining a zeta potential generated between a solid wall and a solution. The method includes (a) injecting an electrolyte solution into a first inlet of a T channel, which is provided with first and second inlet electrodes and a grounded outlet electrode, and a mixed solution of the electrolyte solution and a fluorescent dye into a second channel of the T channel and maintaining a steady-state of the two solutions; (b) applying a direct current electric field from the first and second electrodes to the outlet electrode to form an interface between the electrolyte solution and the mixed solution; (c) applying an alternating current electric field from one of the two inlet electrodes to the outlet electrode to oscillate the interface; and (d) measuring an amplitude of oscillation of the interface and determining the zeta potential from the standard relationship between the zeta potential and the amplitude.
    Type: Application
    Filed: October 31, 2003
    Publication date: July 22, 2004
    Inventors: Yoon-Kyoung Cho, Sang-Min Shin, In-Seok Kang, Geun-Bae Lim
  • Patent number: 6749735
    Abstract: An electromobility focusing controlled channel electrophoresis system includes a first separation channel including an electric field intensity gradient profile in which the intensity is a continuous function of position within the channel over at least a portion of the channel, and the electrophoretic migration facilitated by the electric field is countered by an opposing force, which can be an electroosmotic flow force, to focus analyte species in the separation channel. A second channel including an analyte concentrator and a collection or transfer port is fluidly connected to the first channel by a steering valve facilitating manipulation of separated analyte species. Means for altering and controlling the electroosmotic force for moving analytes within the system and detectors configured for detecting analyte species are also included.
    Type: Grant
    Filed: March 16, 2000
    Date of Patent: June 15, 2004
    Inventor: David Le Febre
  • Publication number: 20040084312
    Abstract: Polymeric surfactants (molecular micelles) are disclosed for use in open tubular capillary electrochromatography or in high performance liquid chromatography. For example, fused silica capillaries are coated with thin films of charged polymers in a polyelectrolyte multilayer (PEM). A PEM coating may be formed in situ by alternate rinses with positive and negative polyelectrolytes. At least the innermost of the negatively charged polymer layers is a molecular micelle. Prototype embodiments have successfully separated seven benzodiazepines from one another. The run-to-run, day-to-day, week-to-week and capillary-to-capillary reproducibilities were very good, with relative standard deviation values less than 0.01. The PEM-coated capillary was very robust over at least 200 runs. Stability against high and low pH values was also observed.
    Type: Application
    Filed: October 30, 2002
    Publication date: May 6, 2004
    Inventors: Isiah M. Warner, Joseph B. Schlenoff, Constantina P. Kapnissi, Mary W. Kamande, Bertha C. Valle
  • Publication number: 20040069634
    Abstract: A method for coating a substrate with silane that comprises contacting in an inert environment a substrate with a vapor containing a bifunctional silane, preferably a bifunctional silane containing an acrylic functionality. The method may further comprise the step of attaching a coating of polyacrylamide to the acrylic functionality by in-situ polymerization or the step of immobilizing acrylic-modified molecules by copolymerization with the acrylic functionality of the bifunctional silane. The substrate may be a capillary, a microchip, a bead, or a slide, preferably of glass. A substrate coated using the instant method, as well as a method for reducing EOF in capillaries used for electrophoresis are also disclosed.
    Type: Application
    Filed: October 11, 2002
    Publication date: April 15, 2004
    Inventor: David K. Hanzel
  • Patent number: 6706161
    Abstract: Methods and compositions for modifying the surface of a polymeric substrate are provided. In the subject methods, at least a portion of the surface of the polymeric substrate is contacted with a biofouling resistant surfactant composition. At least a portion of the surfactant molecules of the composition are end modified with a non-reactive, charged end group that is charge stable over a pH range of a bout 2 to 12. The subject methods and compositions find particular use with electrophoretic devices, such as capillary electrophoretic devices.
    Type: Grant
    Filed: June 10, 1998
    Date of Patent: March 16, 2004
    Assignee: Agilent Technologies, Inc.
    Inventors: Sally A. Swedberg, Karla M. Robotti, Karin Caldwell
  • Publication number: 20040045828
    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.
    Type: Application
    Filed: September 9, 2002
    Publication date: March 11, 2004
    Inventors: Chitra K. Ratnayake, Isabel C. Flores
  • Publication number: 20040040849
    Abstract: A method for collecting an analyte species from a sample is provided, the method of collection potentially being supplemented to give a method of preparing a sample for analysis and/or a method of analysis. The method including providing part of a sample in a substrate, causing the sample to migrate to an interface between the substrate and a second substrate due to the action of an electrical potential difference, the electrophoretic velocity of the analyte species of the second substrate being balanced by or exceeded by the bulk flow velocity of the second substrate and the bulk flow velocity of the second substrate being in an opposing direction to the electrophoretic velocity of the analyte species in the second substrate. In this way substantial concentration of the analyte species at the interface is provided. Subsequently the species can be conveyed away from the interface for further preparation and/or analysis.
    Type: Application
    Filed: June 17, 2003
    Publication date: March 4, 2004
    Applicant: The Secretary of State for the Home Department, Birmingham, United Kingdom
    Inventors: Silvia Valussi, Andreas Manz
  • Publication number: 20030230489
    Abstract: A low-dispersion methodology for designing microfabricated conduction channels for on-chip electrokinetic-based systems is presented. The technique relies on trigonometric relations that apply for ideal electrokinetic flows, allowing faceted channels to be designed on chips using common drafting software and a hand calculator. Flows are rotated and stretched along the abrupt interface between adjacent regions with differing permeability. Regions bounded by interfaces form flow “prisms” that can be combined with other designed prisms to obtain a wide range of turning angles and expansion ratios while minimizing dispersion. Designs are demonstrated using two-dimensional numerical solutions of the Laplace equation.
    Type: Application
    Filed: June 6, 2003
    Publication date: December 18, 2003
    Inventors: Eric B. Cummings, Gregory J. Fiechtner
  • Publication number: 20030217924
    Abstract: The invention provides uncharged water-soluble silica-adsorbing polymers for suppressing electroendoosmotic flow and to reduce analyte-wall interactions in capillary electrophoresis. In one aspect of the invention, one or more of such polymers are employed as components of a separation medium for the separation of biomolecules, such as polynucleotides, polysaccharides, proteins, and the like, by capillary electrophoresis. Generally, such polymers are characterized by (i) water solubility over the temperature range between about 20° C. to about 50° C., (ii) concentration in a separation medium in the range between about 0.001% to about 10% (weight/volume), (iii) molecular weight in the range of about 5×103 to about 1×106 daltons, and (iv) absence of charged groups in an aqueous medium having pH in the range of about 6 to about 9.
    Type: Application
    Filed: December 28, 2001
    Publication date: November 27, 2003
    Applicant: PE Corporation (NY)
    Inventors: Ramakrishna S. Madabhushi, Steven M. Menchen, J. William Efcavitch, Paul D. Grossman
  • Publication number: 20030196896
    Abstract: A method and apparatus are disclosed for screening separation media for performance in capillary electrophoresis. In one aspect the invention comprises concurrently loading a plurality of capillaries from one corresponding end of each with a respective plurality of separation media, adding a sample to each capillary, advancing the samples through the capillaries under an applied electric field, measuring a property of the samples or components thereof as they advance through the capillaries, and using the measured properties to identify one or more preferred sets of separation media. At least one of the steps of loading or advancing are carried out simultaneously over the plurality of capillaries.
    Type: Application
    Filed: April 17, 2002
    Publication date: October 23, 2003
    Inventors: Thomas Harding McWaid, Oleg Kolosov, Gerrit Klaerner, Miroslav Petro, Son Hoai Nguyen, Sigrid Kuebler
  • Publication number: 20030127329
    Abstract: One embodiment of the invention relates to a microfluidic apparatus for controlling fluid flow velocity during electroosmotic flow. According to one aspect of the invention, a voltage applied to a gate electrode modulates flow velocity within an associated microchannel, where the gate voltage is separate from any voltage used to induce electroosmotic flow. According to another aspect of the invention, the flow control apparatus combines multiple gate electrodes to control flow in a microfluidic network. According to one embodiment of the invention, the flow control apparatus is fabricated in a planar silicon substrate. According to another embodiment of the invention, the flow control apparatus is fabricated using polymer materials.
    Type: Application
    Filed: June 1, 2002
    Publication date: July 10, 2003
    Inventors: Donald Lad DeVoe, Cheng S. Lee
  • Patent number: 6586065
    Abstract: It is to provide a capillary having adsorbed a polymer. A capillary having absorbed on an inner wall of the capillary, an ionic polymer having positive electric charge and an ionic polymer having negative electric charge alternately, and a process for producing the same.
    Type: Grant
    Filed: June 1, 1999
    Date of Patent: July 1, 2003
    Assignee: Eisai Co., Ltd.
    Inventors: Hiroyuki Katayama, Yasushi Ishihama
  • Patent number: 6569305
    Abstract: The present invention is a method for injection and stacking of analytes in high salt samples. This stacking method works with both pressure injection or electrokinetic injection. The ability to stack analytes with electrokinetic injection allows the translation of high-salt stacking from the capillary to the microchip format.
    Type: Grant
    Filed: October 15, 1999
    Date of Patent: May 27, 2003
    Inventors: James Palmer, James P. Landers
  • Publication number: 20030075447
    Abstract: The present invention provides for a column for use in capillary electrochromatography including a tube, wherein the tube includes an inner surface having a positively or negatively charged, chemically-bonded stationary coating thereon. The present invention further provides for a method of making a column for use in capillary electrochromatography, including a tube, wherein the tube includes an inner surface having a positively or negatively charged chemically-bonded stationary coating thereon, wherein the steps include filling the column with a sol-gel solution, maintaining the sol-gel solution within the column, and forcing the sol-gel solution out of the column with an inert gas. Further, the present invention provides for a method of analytical separation with a column including an inner layer having a positively charged chemically-bonded stationary coating thereon that reverses the direction of electroosmotic flow in the column compared with a column without the positive surface charge.
    Type: Application
    Filed: January 24, 2002
    Publication date: April 24, 2003
    Inventors: Abdul Malik, James D. Hayes
  • Publication number: 20030042140
    Abstract: The present invention is directed to a method for controlling electroosmotic flow by treating a surface with an organosilane having a single leaving group and optionally a ceramic oxide. This protective coating allows increased control and stabilization of electroosmotic flow by applying a radial voltage field.
    Type: Application
    Filed: October 21, 2002
    Publication date: March 6, 2003
    Applicant: Arizona Board of Regents
    Inventor: Mark A. Hayes
  • Patent number: 6508273
    Abstract: The present invention relates to a device for controlling a liquid flow in a liquid channel, comprising: an elongate liquid holder in which a liquid channel is provided in longitudinal direction; first voltage means for applying a first voltage difference over substantially the longitudinal direction of the liquid channel; a conductor member arranged in at least a part of the liquid channel against the liquid holder; an insulator member arranged in the liquid channel against at least the conductor member; second voltage means for providing a second voltage difference between the conductor member and the liquid in the liquid channel; wherein the thickness of the insulator member is a maximum of 1 &mgr;m and preferably in the order of magnitude of some tens of nanometres.
    Type: Grant
    Filed: July 5, 2001
    Date of Patent: January 21, 2003
    Assignee: Universiteit Twente (Mesa Research Instituut)
    Inventor: Albert Van Den Berg
  • Patent number: 6488831
    Abstract: The present invention is directed to a method for controlling electroosmotic flow by treating a surface with an organosilane having a single leaving group and optionally a ceramic oxide. This protective coating allows increased control and stabilization of electroosmotic flow by applying a radial voltage field.
    Type: Grant
    Filed: August 30, 2000
    Date of Patent: December 3, 2002
    Assignee: Arizona Board of Regents Arizona State University
    Inventor: Mark A. Hayes
  • Publication number: 20020166768
    Abstract: The present invention provides methods of electrophoretically separating macromolecular species, as well as compositions and systems useful in carrying out such methods. Specifically, the methods of the present invention comprise providing a substrate that has at least a first capillary channel disposed therein. The surface of the channel has a first surface charge associated therewith, and is filled with a water soluble surface adsorbing polymer solution that bears a net charge that is the same as the charge on the capillary surface.
    Type: Application
    Filed: May 24, 2002
    Publication date: November 14, 2002
    Applicant: Caliper Technologies Corp.
    Inventor: Robert S. Dubrow
  • Patent number: 6475722
    Abstract: The present invention discloses methodologies for the treatment of the surface(s) of DNA processing devices so as to greatly reduce DNA adsorption to the surface(s) exposed to the DNA-containing media. These aforementioned surface treatments include: (i) the deposition of thin-films of silicon-rich, silicon nitride and of hydroxyl-containing,low-temperature silicon oxide and (ii) the washing of surface with a basic, oxidative wash solution. The present invention also discloses the fabrication of DNA processing devices utilizing surface(s) treated by the methods described above. Such DNA processing devices include, for example, miniaturized electrophoresis and other DNA separation devices, miniaturized PCR reactors, and the like. The present invention further discloses methodologies for testing the degree of DNA adherence to a given surface. Additionally, the methodologies and devices of the present invention are also applicable to the processing of nucleic acids, in generally.
    Type: Grant
    Filed: November 16, 1998
    Date of Patent: November 5, 2002
    Assignee: CuraGen Corporation
    Inventor: Steven A. Henck