Anthony Stephen Cheng

US Patent:

6800608, Oct 5, 2004

Filed:

Jun 22, 2001

Appl. No.:

09/888005

Inventors:

Anthony K. Cheng - Anaheim CA
Julie S. Kim - Placentia CA

Assignee:

Beckman Coulter, Inc. - Fullerton CA

International Classification:

A61K 3800

US Classification:

514 8, 514 2, 435 75, 436533, 530322

Abstract:

This invention relates to stabilized formulations comprising a glycopeptide antibiotic immobilized on carrier particles, and more particularly stabilized vancomycin bidentate conjugate formulations for assaying the concentration of vancomycin in a test sample. The invention also relates to assay formats that utilize such stabilized formulations. The invention further provides a test kit for detecting the presence of vancomycin in a test sample, wherein the test kit includes a stabilized vancomycin conjugate formulation. The invention further provides a novel rate enhancer for immunoassays for enhancing the rate of binding of an anti-analyte antibody to the analyte.

US Patent:

7179658, Feb 20, 2007

Filed:

Sep 6, 2001

Appl. No.:

09/947990

Inventors:

Anthony K. Cheng - Anaheim CA, US
Julie S. Kim - Placentia CA, US
Chan S. Oh - Chino Hills CA, US

Assignee:

Beckman Coulter, Inc. - Fullerton CA

International Classification:

G01N 33/543

US Classification:

436518, 435 71, 435 792, 436172, 436524, 204451

Abstract:

The invention provides highly sensitive and rapid homogeneous assays which employ particle-enhanced assay formats in concert with capillary electrophoresis and laser-induced fluorescence (LIF) detection to determine the concentration of an analyte of interest in a sample. Such a determination is made by measuring fluorescent signal(s) (i. e. , an electropherogram) produced upon LIF of species present in the reaction mixture that are capable of producing such signals. The method of this invention produces simplified electropherograms by reducing the number of signals that must be separated and subsequently measured, and therefore increases the accuracy of the detection and/or quantification of target analyte concentration in a sample.

US Patent:

7556932, Jul 7, 2009

Filed:

Dec 14, 2006

Appl. No.:

11/611072

Inventors:

Anthony K. Cheng - Anaheim CA, US
Julie S. Kim - Placentia CA, US
Chan S. Oh - Chino Hills CA, US

Assignee:

Beckman Coulter, Inc. - Fullerton CA

International Classification:

G01N 33/00

US Classification:

435 794, 435 71, 435 792, 436172, 436518, 436524, 204451

Abstract:

The invention provides highly sensitive and rapid homogeneous assays which employ particle-enhanced assay formats in concert with capillary electrophoresis and laser-induced fluorescence (LIF) detection to determine the concentration of an analyte of interest in a sample. Such a determination is made by measuring fluorescent signal(s) (i. e. , an electropherogram) produced upon LIF of species present in the reaction mixture that are capable of producing such signals. The method of this invention produces simplified electropherograms by reducing the number of signals that must be separated and subsequently measured, and therefore increases the accuracy of the detection and/or quantification of target analyte concentration in a sample.

US Patent:

57053537, Jan 6, 1998

Filed:

Jun 7, 1995

Appl. No.:

8/483288

Inventors:

Chan S. Oh - Chino Hills CA
Julie S. Kim - Placentia CA
Anthony K. Cheng - Anaheim CA

Assignee:

Beckman Instruments, Inc. - Fullerton CA

International Classification:

G01N 3353
G01N 33537
G01N 33543

US Classification:

435 792

Abstract:

An assay for determining the presence of an analyte of interest in a test sample containing an interfering substance that interferes with the assay is disclosed. The assay comprises the steps of forming a reaction mixture by combining in an assay medium (i) an assay system containing components for detecting the analyte of interest, (ii) a test sample containing the analyte and an interfering substance, and (iii) an additional amount of the interfering substance in a quantity sufficient to substantially mask the effect of the interfering substance in the test sample. This reaction mixture is incubated under conditions sufficient to allow complex formation. This resultant complex formation is detected and the presence of the analyte in the test sample is determined.

US Patent:

58495991, Dec 15, 1998

Filed:

Feb 7, 1997

Appl. No.:

8/797384

Inventors:

Chan S. Oh - Diamond Bar CA
Anthony K. Cheng - Brea CA
Josephine M. Michael - Placentia CA
Thomas S. Dobashi - Rosemead CA

Assignee:

Beckman Instruments, Inc. - Fullerton CA

International Classification:

G01N 3353

US Classification:

436501

Abstract:

A method for making a preconjugate which includes immunogenic species of a polymorphic analyte. The method is carried out by reacting an activated binding moiety, and a polymorphic analyte at room temperature for between about 10 hours and about 60 hours. The attaching reaction results in an excess of the preconjugate which includes the immunogenic species of the polymorphic analyte. The preconjugate can be used to make an immunoreactive conjugate useful as a developer antigen in a competitive inhibition immunoassay for the polymorphic analyte.

US Patent:

56270801, May 6, 1997

Filed:

Jul 29, 1994

Appl. No.:

8/283116

Inventors:

Anthony K. Cheng - Anaheim CA
Julie S. Kim - Placentia CA
Chan S. Oh - Chino Hills CA

Assignee:

Beckman Instruments, Inc. - Fullerton CA

International Classification:

G01N 33546

US Classification:

436534

Abstract:

Methods for modulating the rates and dose responses of immunoassays through the incorporation of one or more detergents into the immunoassay reaction are disclosed. The methods are particularly suitable for automated immunoassay formats, especially with formats that use analyte-biotin bidentate reagents. The methods may be used to facilitate the detection of any desired, preselected pharmacological agent.

US Patent:

54400236, Aug 8, 1995

Filed:

Sep 18, 1992

Appl. No.:

7/947710

Inventors:

Anthony K. Cheng - Brea CA
Thomas S. Dobashi - Rosemead CA

Assignee:

Beckman Instruments, Inc. - Fullerton CA

International Classification:

C07K 1700
G01N 33531
C07C 5500
C07C22700

US Classification:

530405

Abstract:

A method for making a valproic acid derivative comprising a functionalized spacer arm attached to a. delta. carbon atom of a valproic acid molecule is disclosed. The method proceeds by attaching a spacer arm joined to an inorganic moiety to a valproic acid precursor to make an alkylated compound, derivatizing the alkylated compound in a liquid medium to make the valproic acid derivative, and then separating the valproic acid derivative from the liquid medium. The valproic acid derivative can be used to make an immunoreactive valproic acid conjugate.

US Patent:

57473528, May 5, 1998

Filed:

May 23, 1994

Appl. No.:

8/248479

Inventors:

Cheng F. Yan - Irvine CA
Chan S. Oh - Chino Hills CA
Anthony K. Cheng - Anaheim CA

Assignee:

Beckman Instruments, Inc. - Fullerton CA

International Classification:

G01N 33547

US Classification:

436533

Abstract:

Bidentate reagents for rapidly and quantitatively assaying the concentration of pharmacological agents in biological samples are described. The reagents are used in an immunoassay format for determining the concentration of desired, preselected pharmacological agents, such as benzoylecgonine, cocaine, an opiate, PCP, digoxigenin, acetaminophen, carbamazepine, phenytoin, primidone, theophylline, an aminoglycoside antibiotic, vancomycin, quinidine or a cannabinoid.