Sue Ji Lee

US Patent:

61746908, Jan 16, 2001

Filed:

Jan 7, 1999

Appl. No.:

9/226695

Inventors:

Ronald L. Manger - Edmonds WA
Linda S. Leja - Everett WA
Sue Y. Lee - Kent WA
James M. Hungerford - Bothell WA
Marleen M. Wekell - Redmond WA

Assignee:

The United States of America as represented by the Department of Health and
Human Services - Washington DC

International Classification:

G01N 33567

US Classification:

435 721

Abstract:

A cell bioassay is provided for determining the presence in a fluid sample of a sodium channel-activating toxin wherein (a) a fluid sample is incubated in the presence of a culture of cells which express voltage-gated sodium channels and which are responsive in a dose-dependent manner to sodium channel-activating toxins and a medium comprising an agent which causes persistent activation of the voltage-gated sodium channel; (b) the culture is incubated with a medium comprising an indicator which is acted upon by living cells to generate a discernable result, (c) the culture is observed for an incidence of the result, and an observation of the result is correlated with the presence of the toxin in the sample. A simplified assay where steps (a) and (b) are effected together also is provided, as is a cell bioassay for determining the sodium channel affect of a toxin in a fluid sample. A competitive assay for sodium channel-blocking toxins also is provided wherein the fluid sample and culture of cells are incubated with a medium comprising (i) an agent which causes persistent activation of the voltage-gated sodium channel and (ii) a sodium channel-activating toxin.

US Patent:

54200113, May 30, 1995

Filed:

Apr 12, 1993

Appl. No.:

8/045067

Inventors:

Ronald L. Manger - Edmonds WA
Linda S. Leja - Lynnwood WA
Sue Y. Lee - Mill Creek WA
James M. Hungerford - Bothell WA
Marleen M. Wekell - Redmond WA

Assignee:

The United States of America as represented by the Department of Health
and Human Services - Washington DC

International Classification:

G01N 33567

US Classification:

435 721

Abstract:

An inventive bioassay method can be used to determine the presence in a fluid sample of a toxin having sodium channel-affecting activity. The method includes the steps of incubating a plurality of cultures of cells which are responsive in a dose-dependent manner to sodium channel-affecting toxins with (i) a medium comprising a solution of ouabain and veratridine and (ii) a portion of the fluid sample, each culture being incubated with a different concentration of the fluid sample; removing the medium and fluid sample from the cultures; incubating the cultures with a medium comprising an indicator which is acted upon by living cells to form a measurable product; measuring the amounts of product formed during the preceding step; and relating the amounts of product measured to a standard calibration curve to determine the presence of the toxin in the sample. The method is readily embodied in kit form and is amenable to automation.

US Patent:

58586873, Jan 12, 1999

Filed:

May 26, 1995

Appl. No.:

8/450877

Inventors:

Ronald L. Manger - Edmonds WA
Linda S. Leja - Everett WA
Sue Y. Lee - Kent WA
James M. Hungerford - Bothell WA
Marleen M. Wekell - Redmond WA

Assignee:

The United States of America as represented by the Department of Health
and Human Services - Washington DC

International Classification:

G01N 33567

US Classification:

435 721

Abstract:

A cell bioassay is provided for determining the presence in a fluid sample of a sodium channel-activating toxin wherein (a) a fluid sample is incubated in the presence of a culture of cells which express voltage-gated sodium channels and which are responsive in a dose-dependent manner to sodium channel-activating toxins and a medium comprising an agent which causes persistent activation of the voltage-gated sodium channel; (b) the culture is incubated with a medium comprising an indicator which is acted upon by living cells to generate a discernable result, (c) the culture is observed for an incidence of the result, and an observation of the result is correlated with the presence of the toxin in the sample. A simplified assay where steps (a) and (b) are effected together also is provided, as is a cell bioassay for determining the sodium channel affect of a toxin in a fluid sample. A competitive assay for sodium channel-blocking toxins also is provided wherein the fluid sample and culture of cells are incubated with a medium comprising (i) an agent which causes persistent activation of the voltage-gated sodium channel and (ii) a sodium channel-activating toxin.