US5423989A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Plasma forming device
Assignee: ChemTrak Inc
•
Filing: 1993-01-21
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Granted: 1995-06-13
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Expires: 2013-01-21
Abstract
Abstract Devices are provided for producing plasma or serum from blood samples, where the plasma or serum is substantially free of red blood cells, hemoglobin, and metabolites and degradation products thereof. The sample can be used in various assays without interference from the interfering components of red blood cells.
Inventors
- 👤 Michael P. Allen
- 👤 Robert B. Shibuya
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 14:21
CPC Classifications
C; C12; C12Q; C12Q1/00; C12Q1/26; C12Q1/54; C12Q1/60; G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/52; G01N33/525; Y; Y10; Y10T; Y10T436/00; Y10T436/25; Y10T436/25375; Y10T436/255
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
178 words
A method of separating red blood cells in a blood separation device comprising a depth filter, wherein blood is separated without significant lysis of the cells or freeing of hemoglobin, said method comprising: adding blood to said depth filter, wherein said depth filter comprises a glass fiber filter having pores in the range of about 1 to 20μ comprising glass fibers of a diameter in the range of about 0.5-9μ, a density of about 40 to 200 g/m 3 and pre-treated with a solution comprising from about 0.01 to 5% by weight of a fibrous protein, wherein a membrane is in fluid receiving relationship with said depth filter, wherein said membrane is a non-asymmetric membrane and has a porosity in the range of about 0.2 to 7μ or an asymmetric membrane and has a minimum porosity not less than about 0.2μ and a maximum porosity not exceeding about 40μ, whereby said blood flows through said device by at least one of capillary action and gravity; and collecting the substantially red-blood-cell- and hemoglobin-free serum or plasma from said device.
Claim 2
Independent Claim
178 words
A method of separating red blood cells in a blood separation device comprising a depth filter, wherein blood is separated without significant lysis of the cells or freeing of hemoglobin, said method comprising: adding blood to said depth filter, wherein said depth filter comprises a glass fiber filter having pores in the range of about 1 to 20μ comprising glass fibers of a diameter in the range of about 0.5-9μ, a density of about 40 to 200 g/m 3 and pre-treated with a solution comprising from about 0.01 to 5% by weight of a fibrous protein, wherein a membrane is in fluid receiving relationship with said depth filter, wherein said membrane is a non-asymmetric membrane and has a porosity in the range of about 0.2 to 7μ or an asymmetric membrane and has a minimum porosity not less than about 0.2μ and a maximum porosity not exceeding about 40μ, whereby said blood flows through said device by at least one of capillary action and gravity; and collecting the substantially red-blood-cell- and hemoglobin-free serum or plasma from said device.
Claim 3
Dependent Claim
12 words
A method according to claim 1, wherein said fibrous protein is gelatin.
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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) | 1998-06-12 | 1998-12-12 | 1999-06-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-06-12 | 2002-12-12 | 2003-06-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-06-12 | 2006-12-12 | 2007-06-13 | $7700.00 | Window Closed / Lapsed |