Patent US4923680A successfully refreshed from Google Patents.
US4923680A
Expired / Lapsed
US
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Test device containing an immunoassay filter with a flow-delaying polymer
Assignee: Clinical Diagnostic Systems Inc
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Filing: 1987-09-18
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Granted: 1990-05-08
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Expires: 2007-09-18
Abstract
Abstract There is disclosed a filter and a device positioning the filter between an upper and a lower chamber, particularly useful in an immunoassay. The filter and device are improved in that the membrane comprising the filter is overcoated with at least one water-soluble polymer of a type, a molecular weight, and at a dry-solids coverage effective to create for that membrane an induction time at room temperature of at least about 30 seconds and no greater than about 300 seconds, for a liquid head of pressure of about 6 mm of water.
Inventors
- 👤 Roger W. Nelson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:44
CPC Classifications
B; B01; B01D; B01D67/00; B01D67/0081; B01D67/0088; B01D61/00; B01D61/14; B01D61/18; B01D69/00; B01D69/12; B01D69/1213; B01D69/1218; G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/53; G01N33/5302; G01N33/543; G01N33/54366; Y; Y10; Y10S; Y10S436/00; Y10S436/807
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
143 words
In a reaction test device, comprising an upper reaction compartment, a lower fluid collection compartment, and a filter separating the two compartments and comprising a membrane having pores sized to retain selected material and to pass through a solvent, said lower compartment including means for drawing liquid from the upper to the lower compartment through the filter, the improvement wherein said filter further comprises a first water-soluble polymer on and within portions of said membrane, and an additional water-soluble polymer applied on said at least one polymer after the latter is dry, said polymers being of a type, a molecular weight and a dry solids coverage effective to create for said membrane an induction time at room temperature of at least about 30 seconds and no greater than about 300 seconds, for a liquid head of pressure of about 6 mm of water.
Claim 2
Dependent Claim
143 words
In a reaction test device, comprising an upper reaction compartment, a lower fluid collection compartment, and a filter separating the two compartments and comprising a membrane having pores sized to retain selected material and to pass through a solvent, said lower compartment including means for drawing liquid from the upper to the lower compartment through the filter, the improvement wherein said filter further comprises a first water-soluble polymer on and within portions of said membrane, and an additional water-soluble polymer applied on said at least one polymer after the latter is dry, said polymers being of a type, a molecular weight and a dry solids coverage effective to create for said membrane an induction time at room temperature of at least about 30 seconds and no greater than about 300 seconds, for a liquid head of pressure of about 6 mm of water.
Claim 3
Dependent Claim
28 words
A device as defined in claim 1, wherein said first polymer is selected from the group consisting of polyvinyl alcohol, polyvinyl pyrrolidone and copolymers thereof, carboxymethylcellulose, and carboxyethylcellulose.
Claim 4
Dependent Claim
28 words
A device as defined in claim 1 wherein said additional polymer is selected from the group consisting of polyvinyl alcohol, polyvinyl pyrrolidone and copolymers thereof, carboxymethylcellulose, and carboxyethylcellulose.
Claim 5
Dependent Claim
26 words
A device as defined in claim 1 wherein said additional polymer and said at least one polymer have the same chemical structure but different molecular weights.
Claim 6
Dependent Claim
22 words
A device as defined in claim 1, and further including an immunoreagent on said filter, selected from an antibody or an antigen.
Claim 7
Dependent Claim
23 words
A test device as defined in claim 1, wherein said second polymer is applied together with about 1 to 3 wt % glycerol.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-05-07 | 1993-11-06 | 1994-05-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-05-07 | 1997-11-06 | 1998-05-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-05-07 | 2001-11-06 | 2002-05-08 | $7700.00 | Window Closed / Lapsed |