Patents by Inventor Jia-Li Liao

Jia-Li Liao 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: 6423666
    Abstract: Chromatographic beads with pores large enough to serve as through-channels for fast diffusion and a substantial absence of pores of smaller diameters that would cause band broadening due to slow diffusive transport, are formed by suspension polymerization of an aqueous solution of a monomer mixture that includes a total monomer (combination of polymer backbone monomer and crosslinking agent) concentration of 2% to 50% by weight relative to the aqueous solution and a crosslinking agent in an amount such that the mole ratio of crosslinking agent to total monomer is from about 0.1 to about 0.7. The suspension polymerization process involves forming a suspension of aqueous droplets of the monomer mixture in an organic phase.
    Type: Grant
    Filed: October 5, 1999
    Date of Patent: July 23, 2002
    Assignee: Bio-Rad Laboratories, Inc.
    Inventors: Jia-Li Liao, Stellan Hjerten
  • Patent number: 6054053
    Abstract: Peak resolution in reversed-phase electrochromatography is improved in either of two alternative ways. The first is by a stepwise increase in the concentration of acetonitrile or other equivalent buffer constituent or modifier after the sample has been loaded, and the second is the inclusion of a surfactant in the mobile phase.
    Type: Grant
    Filed: May 18, 1999
    Date of Patent: April 25, 2000
    Assignee: Bio-Rad Laboratories, Inc.
    Inventors: Stellan Hjerten, Jia-Li Liao
  • Patent number: 5938930
    Abstract: Peak resolution in reversed-phase electrochromatography is improved in either of two alternative ways. The first is by a stepwise increase in the concentration of acetonitrile or other equivalent buffer constituent or modifier after the sample has been loaded, and the second is the inclusion of a surfactant in the mobile phase.
    Type: Grant
    Filed: September 29, 1997
    Date of Patent: August 17, 1999
    Assignee: Bio-Rad Laboratories, Inc.
    Inventors: Stellan Hjerten, Jia-Li Liao
  • Patent number: 5935429
    Abstract: A chromatography column with a continuous solid bed spanning the cross section of the column, the bed containing channels large enough for hydrodynamic flow, is prepared by polymerizing a mixture of monomers and ammonium sulfate in an aqueous solution. The monomers include a monofunctional monomer such as a vinyl, allyl, acrylic, or methacrylic compound, and a polyfunctional monomer (i.e., a crosslinker), the total monomer concentration being in the range of 10% to 20% by weight, the mole ratio of crosslinker to total monomer being in the range of 0.3 to 0.4, and the ammonium sulfate having a concentration in the range of 0.4 M to 0.8 M. Functional groups to impart specialized separation capabilities, notably anion and cation exchange, can be included in the monomer mixture.
    Type: Grant
    Filed: November 5, 1997
    Date of Patent: August 10, 1999
    Assignee: Bio-Rad Laboratories, Inc.
    Inventors: Jia-Li Liao, Stellan Hjerten
  • Patent number: 5916445
    Abstract: Chromatographic media that demonstrate an artificially created recognition of any preselected molecular species with only can affinity-type adsorption are formed by polymerization from solutions of non-ionizable monomers with a quantity of the species contained in the solution, followed by removal of the species by conventional washing. The media are of particular utility and interest when used to achieve affinity binding of proteins. Uses of the media include chromatography and the general isolation and removal of the adsorbed species.
    Type: Grant
    Filed: October 13, 1997
    Date of Patent: June 29, 1999
    Assignee: Bio-Rad Laboratories, Inc.
    Inventors: Stellan Hjerten, Jia-Li Liao
  • Patent number: 5814223
    Abstract: Chromatographic media that demonstrate an artificially created recognition of any preselected molecular species with only an affinity-type adsorption are formed by polymerization from solutions of non-ionizable monomers with a quantity of the species contained in the solution, followed by removal of the species by conventional washing. The media are of particular utility and interest when used to achieve affinity binding of proteins. Uses of the media include chromatography and the general isolation and removal of the adsorbed species.
    Type: Grant
    Filed: October 31, 1997
    Date of Patent: September 29, 1998
    Assignee: Bio-Rad Laboratories, Inc.
    Inventors: Stellan Hjerten, Jia-Li Liao
  • Patent number: 5766435
    Abstract: The present invention provides new methods for the concentration of ionic solutes, particularly ampholytes, such as, for example, peptides, proteins and nucleic acids. The methods are based on the fact that the electrophoretic migration velocities of solutes decrease upon a decrease in the absolute value of the zeta-potential of a solute or the pore size of the electrophoresis medium, and upon an increase in the cross-section of the electrophoresis chamber, the viscosity of the electrophoresis medium, or the electrical conductivity of the electrophoresis medium. When applied to capillary electrophoresis, the methods described herein permit concentration of a solution of solutes in the same capillary tube as is used for the electrophoretic analysis. Alternatively, however, the sample can be withdrawn from the capillary tube following concentration of the solution of solutes and processed by techniques other than high-performance capillary electrophoresis (HPCE).
    Type: Grant
    Filed: March 22, 1996
    Date of Patent: June 16, 1998
    Assignee: Bio-Rad Laboratories, Inc.
    Inventors: Jia-li Liao, Stellan Hjerten, Christopher Siebert
  • Patent number: 5728296
    Abstract: Chromatographic media that demonstrate an artificially created recognition of any preselected molecular species with only an affinity-type adsorption are formed by polymerization from solutions of non-ionizable monomers with a quantity of the species contained in the solution, followed by removal of the species by conventional washing. The media are of particular utility and interest when used to achieve affinity binding of proteins. Uses of the media include chromatography and the general isolation and removal of the adsorbed species.
    Type: Grant
    Filed: March 20, 1996
    Date of Patent: March 17, 1998
    Assignee: Bio-Rad Laboratories, Inc.
    Inventors: Stellan Hjerten, Jia-Li Liao
  • Patent number: 5647979
    Abstract: A separation medium for reversed-phase chromatography is prepared by polymerizing an aqueous vinyl monomer mixture to which a hydrophobic alkyl methacrylate with 3 or more carbon atoms in the alkyl group and a detergent have been added. The further inclusion of a vinyl monomer with a charged group in the reaction mixture produces a separation medium useful for reversed-phase electrochromatography. Performance of the polymerization in a capillary produces a continuous bed inside the capillary. An alternative for non-capillary separations, such as those conducted in larger diameter tubing, is the preparation of the medium in a vessel outside the tubing, followed by granulation of the polymer and placement of the granules in the tubing.
    Type: Grant
    Filed: June 14, 1996
    Date of Patent: July 15, 1997
    Assignee: Bio-Rad Laboratories, Inc.
    Inventors: Jia-Li Liao, Stellan Hjerten
  • Patent number: 5645717
    Abstract: Macromolecular species in a liquid sample are chromatographically separated in a separation medium formed by polymerization of monomers in an aqueous solution with a sufficient amount of crosslinking agent to cause aggregation and precipitation of the polymer chains. The medium is either formed in the column in which chromatography is to take place as a continuous although channeled bed, or in a separate reaction vessel and then transferred to the column in comminuted form as a packed bed. Improvements in the performance of the bed are achieved by compression of the bed.
    Type: Grant
    Filed: March 2, 1995
    Date of Patent: July 8, 1997
    Assignee: Bio-Rad Laboratories, Inc.
    Inventors: Stellan Hjerten, Jia-Li Liao
  • Patent number: 5505831
    Abstract: The present invention provides new methods for the concentration of ionic solutes, particularly ampholytes, such as, for example, peptides, proteins and nucleic acids. The methods are based on the fact that the electrophoretic migration velocities of solutes decrease upon a decrease in the absolute value of the zeta-potential of a solute or the pore size of the electrophoresis medium, and upon an increase in the cross-section of the electrophoresis chamber, the viscosity of the electrophoresis medium, or the electrical conductivity of the electrophoresis medium. When applied to capillary electrophoresis, the methods described herein permit concentration of a solution of solutes in the same capillary tube as is used for the electrophoretic analysis. Alternatively, however, the sample can be withdrawn from the capillary tube following concentration of the solution of solutes and processed by techniques other than high-performance capillary electrophoresis (HPCE).
    Type: Grant
    Filed: January 26, 1993
    Date of Patent: April 9, 1996
    Assignee: Bio-Rad Laboratories, Inc.
    Inventors: Jia-li Liao, Stellan Hjerten, Christopher Siebert
  • Patent number: 5480526
    Abstract: The present invention provides new methods for desalting samples of ionic polymers or weak electrolytes, preferable ampholytes (e.g., peptides, proteins and glycoconjugates) or, compounds which can be transformed into these substances by complex formation. The methods of the present invention are based on the fact that salts can be removed from a sample by electrophoretically replacing the salts with ampholytes present in the ampholytic media of the anolyte and the catholyte or, with displacing cations and anions that have been introduced into the anolyte and catholyte, respectively, and which have mobilities less than the mobilities of the cations and anions to be removed from the sample.Although applicable to both small-volume and large-volume samples, the methods are particularly well suited for small-volume samples. Moreover, when applied to capillary electrophoresis, the methods described herein permit desalting of a sample in the same capillary tube as is used for the electrophoretic analysis.
    Type: Grant
    Filed: June 7, 1994
    Date of Patent: January 2, 1996
    Assignee: Bio-Rad Laboratories, Inc.
    Inventors: Jia-li Liao, Rong Zhang, Christopher Siebert
  • Patent number: 5464517
    Abstract: Electrophoresis is performed in buffers which exhibit both substantial buffering capacity and low electrical conductivity, permitting the separations to be performed at high field strengths without loss of resolution. Four classes of buffering agents are cited as examples:(1) buffering agents with a small number of charged groups per molecule;(2) carrier ampholytes fractionated to a narrow isoelectric point range;(3) low molecular weight buffering ampholytes with an isoelectric point which is close in value to one of the pK values of the ampholyte; and(4) high molecular weight buffering ampholytes in which the acidic and basic groups have the same or very close pK values.These buffering agents are of particular interest in capillary electrophoresis.
    Type: Grant
    Filed: January 30, 1995
    Date of Patent: November 7, 1995
    Assignee: Bio-Rad Laboratories
    Inventors: Stellan Hjerten, Jia-Li Liao
  • Patent number: 5135650
    Abstract: Highly compressible chromatographic stationary phase particles such as agarose beads are made rigid to a degree suitable for use in HPLC, and nonporous to proteins by one of two procedures. The first involves shrinking the beads with the use of an organic solvent in which the agarose bead will neither dissolve nor swell to collapse the porosity, followed by crosslinking the bead surfaces inside the collapsed pores to fix the pores in their collapsed state. The second involves filling the pores (without shrinkage of the beads) with a polymerizable substance which grafts to the pore surface, and performing the graft polymerization. The invention also extends to rigid beads, which are rendered deformable to a limited degree by coating the surface with a polymer. Finally, porous rigid beads are rendered nonporous by polymerizing a polymerizable material inside the pores in the same manner as the porous compressible beads.
    Type: Grant
    Filed: May 2, 1990
    Date of Patent: August 4, 1992
    Assignee: Bio-Rad Laboratories, Inc.
    Inventors: Stellan Hjerten, Jia-Li Liao