US4387031A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Compositions able to separate the erythrocytes from the serum or plasma in blood analysis samples, and the method which uses them
Assignee: Individual
•
Filing: 1981-07-20
•
Granted: 1983-06-07
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Expires: 2001-07-20
Abstract
Abstract Compositions based on polydimethylsiloxane and physiologically inert powdered polymers, which are able to create a sharp separation layer between the erythrocytes and the serum or plasma during the centrifuging of blood samples for medical analyses.
Inventors
- 👤 Luigi Prandi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 15:47
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/5002; B; B01; B01D; B01D43/00; C; C08; C08L; C08L83/00; C08L83/04; G01N33/483; G01N33/487; G01N33/49; G01N33/491; C08G; C08G77/00; C08G77/04
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
86 words
Compositions which are able to separate the erythrocytes from the serum or plasma in a blood analysis sample by centrifuging, and having a specific gravity of between 1.010 and 1.100, characterised by comprising: a--a polydimethylsiloxane of viscosity between 5000 and 60,000 cst and density between 0.965 and 0.980 g/cm 3 b--a chemically and physically inert macromolecular substance of particle size between 0.200 and 450μ and specific gravity between 1.30 and 1.80, chosen from the group consisting of polyolefine resins, polyvinyl resins, fluorinated polyolefines and polyester resins.
Claim 2
Dependent Claim
86 words
Compositions which are able to separate the erythrocytes from the serum or plasma in a blood analysis sample by centrifuging, and having a specific gravity of between 1.010 and 1.100, characterised by comprising: a--a polydimethylsiloxane of viscosity between 5000 and 60,000 cst and density between 0.965 and 0.980 g/cm 3 b--a chemically and physically inert macromolecular substance of particle size between 0.200 and 450μ and specific gravity between 1.30 and 1.80, chosen from the group consisting of polyolefine resins, polyvinyl resins, fluorinated polyolefines and polyester resins.
Claim 3
Dependent Claim
50 words
Compositions as claimed in claim 1, characterised by also comprising: c--a fluid polyisobutylene of viscosity between 0.30 and 250 poises and density between 0.833 and 0.899 g/cm 3 d--amorphous micronised silica of particle size between 5 and 30 nm, apparent density between 30 and 80 g/l, and specific gravity 2.15.
Claim 4
Dependent Claim
54 words
Compositions as claimed in claims 1 or 2, wherein the components are present in the mixture in proportions within the following ranges: ______________________________________
a - polydimethylsiloxane
90-40 parts by weight
b - macromolecular substance
10-34 parts by weight
c - polyisobutylene 0-20 parts by weight
d - micronised silica
0-6 parts by weight
______________________________________
Claim 5
Dependent Claim
25 words
Compositions as claimed in claims 1 or 2, wherein the macromolecular substance is chosen from the group consisting of polyethylene, polyvinylchloride, polyvinylidene fluoride, and polyester.
Claim 6
Independent Claim
33 words
A method for separating the erythrocytes from the serum or blood in blood analysis samples by centrifuging, characterised by using the compositions as claimed in claims 1 or 2 as the separator-filter medium.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-06-06 | 1986-12-06 | 1987-06-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-06-06 | 1990-12-06 | 1991-06-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-06-06 | 1994-12-06 | 1995-06-07 | $7700.00 | Window Closed / Lapsed |