Patents by Inventor Sylvia Khoo

Sylvia Khoo 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: 6740527
    Abstract: Cyanide-free reagents for the determination of hemoglobin and leukocytes present in a blood sample comprise an aqueous solutions of at least one quaternary ammonium salt, preferably selected from the group of alkyltrimethylammonium salts, alkyldimethylbenzylammonium salts or alkylpyridium salts consisting of tetradecyltrimethyl ammonium bromide (TTAB), dodecyltrimethyl ammonium chloride, cetyltrimethyl ammonium bromide, hexadecyltrimethyl ammonium bromide and benzalkonium chlorides, and hydroxylamine salts, especially hydrochloride, sulfate and phosphates and other acid salts. The method involves mixing the reagent with a diluent-diluted blood sample, presenting it to an absorbance spectrophotometer and measuring the resulting optical density as an indicator of hemoglobin concentration. This cyanide-free reagent could be used solely for hemoglobin determinations, or, it can also be used in leukocyte counting and sizing using hematology instrumentation.
    Type: Grant
    Filed: May 27, 1997
    Date of Patent: May 25, 2004
    Assignee: Abbott Laboratories
    Inventors: Show-Chu Wong, Sylvia Khoo
  • Patent number: 5958781
    Abstract: Cyanide-free reagents for the determination of hemoglobin and leukocytes present in a blood sample contain an aqueous solution of at least one quaternary ammonium salt, preferably selected from the group of alkyltrimethylammonium salts, alkyldimethylbenzylammonium salts or alkylpyridium salts consisting of tetradecyltrimethyl ammonium bromide (TTAB), dodecyltrimethyl ammonium chloride, cetyltrimethyl ammonium bromide, hexadecyltrimethyl ammonium bromide and benzalkonium chlorides, and hydroxylamine salts, especially hydrochloride, sulfate and phosphates and other acid salts. The method involves mixing the reagent with a diluent- diluted blood sample, presenting it to an absorbance spectrophotometer and measuring the resulting optical density as an indicator of hemoglobin concentration. This cyanide-free reagent could be used solely for hemoglobin determinations, or , it can also be used in leukocyte counting and sizing using hematology instrumentation.
    Type: Grant
    Filed: May 27, 1997
    Date of Patent: September 28, 1999
    Assignee: Abbott Laboratories
    Inventors: Show-Chu Wong, Sylvia Khoo