Samuel Kin Ho

US Patent:

20040171099, Sep 2, 2004

Filed:

Sep 19, 2003

Appl. No.:

10/665314

Inventors:

James Cali - Verona WI, US
Dieter Klaubert - Arroyo Grande CA, US
William Daily - Santa Maria CA, US
Samuel Ho - New Bedford MA, US
Susan Frackman - Madison WI, US
Erika Hawkins - Madison WI, US
Keith Wood - Mount Horeb WI, US

Assignee:

Promega Corporation

International Classification:

C12Q001/26

US Classification:

435/025000

Abstract:

The present invention provides methods, compositions, substrates, and kits useful for analyzing the metabolic activity in cells, tissue, and animals and for screening test compounds for their effect on cytochrome P450 activity. In particular, a one-step and two-step methods using luminogenic molecules, e.g. luciferin or coelenterazines, that are cytochrome P450 substrates and that are also bioluminescent enzyme, e.g., luciferase, pro-substrates are provided. Upon addition of the luciferin derivative or other luminogenic molecule into a P450 reaction, the P450 enzyme metabolizes the molecule into a bioluminescent enzyme substrate, e.g., luciferin and/or luciferin derivative metabolite, in a P450 reaction. The resulting metabolite(s) serves as a substrate of the bioluminescent enzyme, e.g., luciferase, in a second light-generating reaction. Luminescent cytochrome P450 assays with low background signals and high sensitivity are disclosed and isoform selectivity is demonstrated. The present invention also provides an improved method for performing luciferase reactions which employs added pyrophosphatase to remove inorganic pyrophosphate, a luciferase inhibitor which may be present in the reaction mixture as a contaminant or may be generated during the reaction. The present method further provides a method for stabilizing and prolonging the luminescent signal in a luciferase-based assay using luciferase stabilizing agents such as reversible luciferase inhibitors.

US Patent:

20050026171, Feb 3, 2005

Filed:

Dec 23, 2003

Appl. No.:

10/746995

Inventors:

Erika Hawkins - Madison WI, US
James Cali - Verona WI, US
Samuel Ho - New Bedford MA, US
Martha O'Brien - Madison WI, US
Richard Somberg - Madison WI, US
Robert Bulleit - Verona WI, US
Keith Wood - Mount Horeb WI, US

International Classification:

C12Q001/68
C12Q001/66

US Classification:

435006000, 435008000

Abstract:

A method and kit is provided for enhancing the tolerance of an assay reagent to compounds in an assay sample, the assay reagent including a luciferase enzyme. The method includes contacting the luciferase with a tolerance enhancement agent in an amount sufficient to substantially protect luciferase enzyme activity from interference of the compound and minize interference by at least about 10% relative to an assay not having tolerance enhancement agent.

US Patent:

59681535, Oct 19, 1999

Filed:

Oct 13, 1998

Appl. No.:

9/170812

Inventors:

William R. Wheeler - Southboro MA
Matthew James Adiletta - Worcester MA
Samuel Ho - Marlboro MA
Debra Bernstein - Sudbury MA
Gilbert M. Wolrich - Framingham MA

Assignee:

Digital Equipment Corporation - Houston TX

International Classification:

G06F 1300

US Classification:

710110

Abstract:

A method and apparatus for maximizing the performance of DMA transfers over a PCI. TM. bus are provided which includes a Per-Channel Retry count, Double Buffer Management, Wait Enable functionality, Back Up register functionality, Gather/Scatter mapping, a method for minimization of PIO writes, Read Semaphore functionality, a method for servicing of DMA transfers during FMU latency periods, Valid bit functionality, high and low water thresholds, and re-usable page tables.

US Patent:

58840508, Mar 16, 1999

Filed:

Jun 21, 1996

Appl. No.:

8/668200

Inventors:

William R. Wheeler - Southboro MA
Matthew James Adiletta - Worcester MA
Samuel Ho - Marlboro MA
Debra Bernstein - Sudbury MA
Gilbert M. Wolrich - Framingham MA

Assignee:

Digital Equipment Corporation - Maynard MA

International Classification:

G06F 1300

US Classification:

395287

Abstract:

A method and apparatus for maximizing the performance of DMA transfers over a PCI. TM. bus are provided which includes a Per-Channel Retry count, Double Buffer Management, Wait Enable functionality, Back Up register functionality, Gather/Scatter mapping, a method for minimization of PIO writes, Read Semaphore functionality, a method for servicing of DMA transfers during FMU latency periods, Valid bit functionality, high and low water thresholds, and re-usable page tables.