Patents by Inventor Hon-Peng P. Lau

Hon-Peng P. Lau 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).

  • Use of chromatographic supports having immobilized flocculating agent in separating microparticles
    Patent number: 5447870
    Abstract: Disclosed is a primary chromatographic support containing an immobilized flocculating agent for use as a separation media for a secondary support consisting of microparticles used in affinity separation and heterogeneous immunoassays. In a specific embodiment, a flocculating agent such as polyethyleneimine is immobilized on a chromatographic resin packed in a column. The column so formed is then used to trap microparticles having an affinity ligand or binder for the ligand affixed thereon. Such microparticles are used as a solid support for the affinity reaction involved in a variety of immunoassay formats.
    Type: Grant
    Filed: October 29, 1993
    Date of Patent: September 5, 1995
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Hon-Peng P. Lau
  • Method of performing affinity separation using immobilized flocculating agent on chromatographic support
    Patent number: 5422284
    Abstract: Disclosed is a primary chromatographic support containing an immobilized flocculating agent for use as a separation media for a secondary support consisting of microparticles used in affinity separation and heterogeneous immunoassays. In a specific embodiment, a flocculating agent such as polyethyleneimine is immobilized on a chromatographic resin packed in a column. The column so formed is then used to trap microparticles having an affinity ligand or binder for the ligand affixed thereon. Such microparticles are used as a solid support for the affinity reaction involved in a variety of immunoassay formats.
    Type: Grant
    Filed: October 29, 1993
    Date of Patent: June 6, 1995
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Hon-Peng P. Lau
  • Method for stabilizing an alkanol amine buffer used in optical determinations of enzyme activity
    Patent number: 5397699
    Abstract: A method for stabilizing an alkanol amine buffer against substantial degradation so that enzyme activity can be optically determined in such a buffer is described. Stabilization is achieved by adding a stabilizing effective amount of a stabilizing agent to the buffer wherein the stabilizing agent (i) does not inhibit enzyme activity and (ii) does not interfere substantially with the optical determination in the wavelength region of measurement.
    Type: Grant
    Filed: March 4, 1994
    Date of Patent: March 14, 1995
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: James E. Davis, Hon-Peng P. Lau, Neel V. Neelkantan
  • Stabilization and reduction of background fluorescence of hydroxy coumarin ester enzyme substrates
    Patent number: 5362627
    Abstract: Hydroxy coumarin ester enzyme substrates can be stored in a strong base at pH above 11 to stabilize the substrate against premature hydrolysis of the ester bond and to reduce the revel of contaminating hydroxy coumarin. When diluted in buffer at pH below 11 shortly before use in an enzyme assay, the substrate solution provides low background fluorescence.
    Type: Grant
    Filed: September 12, 1988
    Date of Patent: November 8, 1994
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Richard A. Blumenthal, Hon-Peng P. Lau, Esther K. Yang
  • Chromatographic supports having an immobilized flocculating agent and their use in immunoassays
    Patent number: 5302532
    Abstract: Disclosed is a primary chromatographic support containing an immobilized flocculating agent for use as a separation media for a secondary support consisting of microparticles used in affinity separation and heterogeneous immunoassays. In a specific embodiment, a flocculating agent such as polyethyleneimine is immobilized on a chromatographic resin packed in a column. The column so formed is then used to trap microparticles having an affinity ligand or binder for the ligand affixed thereon. Such microparticles are used as a solid support for the affinity reaction involved in a variety of immunoassay formats.
    Type: Grant
    Filed: April 14, 1989
    Date of Patent: April 12, 1994
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Hon-Peng P. Lau
  • Enzyme-linked immunoassay for measurement of cyclosporin a levels in whole blood samples
    Patent number: 5151348
    Abstract: An enzyme-linked immunoassay for the determination of cyclosporin A levels in whole blood samples is provided based on the utilization of .beta.-D-galactosidase as an enzyme label and chlorophenol red-.beta.-D-galactopyranoside or resorufin-.beta.-D-galactopyranoside as a .beta.-D-galactosidase substrate.
    Type: Grant
    Filed: December 23, 1988
    Date of Patent: September 29, 1992
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Hon-Peng P. Lau, Warren K. Miller
  • Coated chromium dioxide particles
    Patent number: 4661408
    Abstract: Chromium dioxide has favorable magnetic properties which make it desirable as a solid support in heterogeneous immunoassays. However, to be useful in such assays it must be protected against hydrolytic degradation. This invention provides magnetic particles useful in immunoassays having a core of CrO.sub.2 which has a reduced surface, the core coated with silica and further coated with a silane.
    Type: Grant
    Filed: March 18, 1986
    Date of Patent: April 28, 1987
    Assignee: E.I. Du Pont de Nemours and Company
    Inventors: Hon-Peng P. Lau, Esther K. Yang, Howard W. Jacobson