Patents by Inventor Esther K. Yang

Esther K. Yang 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).

  • 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
  • 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