US3858795A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for washing blood cells
Assignee: Thermo IEC Inc
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Filing: 1973-10-23
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Granted: 1975-01-07
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Expires: 1993-10-23
Abstract
Abstract Method for washing blood cells by forcing blood cells to the bottom of a stationary liquid in a container, where the liquid has a greater density at the bottom of the container than at the top.
Inventors
- 👤 John E Joyce
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:25
CPC Classifications
A; A61; A61M; A61M1/00; A61M1/36; A61M1/3693; A61M1/3692; A61M1/3695; G; G01; G01N; G01N1/00; G01N1/28
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
77 words
A method for washing blood cells comprising the steps of loading a vessel with a liquid which is less dense than blood cells in such a manner that the liquid increases in density from the top of the vessel to the bottom thereof, thereafter forcing blood cells to be washed from the top of the vessel toward the bottom of the vessel through the stationary liquid to strip the blood cells and thereby produce washed blood cells.
Claim 2
Independent Claim
77 words
A method for washing blood cells comprising the steps of loading a vessel with a liquid which is less dense than blood cells in such a manner that the liquid increases in density from the top of the vessel to the bottom thereof, thereafter forcing blood cells to be washed from the top of the vessel toward the bottom of the vessel through the stationary liquid to strip the blood cells and thereby produce washed blood cells.
Claim 3
Dependent Claim
20 words
The method as set forth in claim 1 wherein said blood cells are forced through said liquid by a centrifugation.
Claim 4
Independent Claim
109 words
A method for washing blood cells comprising the step of producing a density gradient within a liquid contained by a vessel by introducing two liquids of different densities both of which are less dense than blood cells into separate compartments of a generator, initially allowing the liquids to flow from said compartments to a mixing zone, varying continuously the amount of liquid flowing from one compartment relative to the amount of liquid flowing from a second compartment and delivering said liquids from said mixing zone into a vessel and thereafter forcing blood cells to be washed from the top of the vessel containing a liquid to the bottom thereof.
Claim 5
Independent Claim
109 words
A method for washing blood cells comprising the step of producing a density gradient within a liquid contained by a vessel by introducing two liquids of different densities both of which are less dense than blood cells into separate compartments of a generator, initially allowing the liquids to flow from said compartments to a mixing zone, varying continuously the amount of liquid flowing from one compartment relative to the amount of liquid flowing from a second compartment and delivering said liquids from said mixing zone into a vessel and thereafter forcing blood cells to be washed from the top of the vessel containing a liquid to the bottom thereof.
Claim 6
Dependent Claim
20 words
The method as set forth in claim 3 wherein said blood cells are forced through said liquid by a centrifugation.
Claim 7
Independent Claim
221 words
A method for washing blood cells comprising the steps of: introducing two liquids of different densities both of which are less dense than blood cells into separate compartments of a generator, said generator being located in the upper portion of a vessel having a configuration which enables it to be placed in a centrifuge, each of said compartments having an opening for the flow of liquid into the lower portion of said vessel, said compartments being separated by a partition which causes the amount of liquid flowing from one compartment to continuously vary relative to the amount of liquid flowing from the other compartment, said liquids being introduced into said compartments so that a liquid gradient which increases in density is produced in the lower portion of the vessel; loading a sample of blood to be washed into the lower portion of said vessel; centrifuging the vessel to cause the liquid in the compartments to flow into the lower portion of the vessel and produce a liquid density gradient which increases in density from the top of the vessel to the bottom thereof with the sample of the blood floating on the liquid in the lower portion; and, continuing centrifuging to force the blood cell through the stationary liquid gradient to strip the blood cells and thereby produce washed blood cells.
Claim 8
Independent Claim
221 words
A method for washing blood cells comprising the steps of: introducing two liquids of different densities both of which are less dense than blood cells into separate compartments of a generator, said generator being located in the upper portion of a vessel having a configuration which enables it to be placed in a centrifuge, each of said compartments having an opening for the flow of liquid into the lower portion of said vessel, said compartments being separated by a partition which causes the amount of liquid flowing from one compartment to continuously vary relative to the amount of liquid flowing from the other compartment, said liquids being introduced into said compartments so that a liquid gradient which increases in density is produced in the lower portion of the vessel; loading a sample of blood to be washed into the lower portion of said vessel; centrifuging the vessel to cause the liquid in the compartments to flow into the lower portion of the vessel and produce a liquid density gradient which increases in density from the top of the vessel to the bottom thereof with the sample of the blood floating on the liquid in the lower portion; and, continuing centrifuging to force the blood cell through the stationary liquid gradient to strip the blood cells and thereby produce washed blood cells.
Claim 9
Dependent Claim
38 words
The method as set forth in claim 5 including the step of detaching the lower portion of the vessel away from the upper portion to yield readily accessible washed blood cells in the lower portion of the vessel.
Claim 10
Dependent Claim
27 words
The method as set forth in claim 6 wherein the lower portion is detached from the upper portion by cutting the vessel with a pair of scissors.
Claim 11
Dependent Claim
24 words
The method as set forth in claim 6 wherein the lower portion is sealed to provide a container for storing the washed blood cells.
Claim 12
Dependent Claim
49 words
The method as set forth in claim 5 wherein the lower portion of the vessel is loaded into liquid which is denser than the blood cells to provide a dense cushion which prevents the blood cells from reaching the bottom of the lower portion of the vessel when centrifuged.
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) | 1978-01-06 | 1978-07-08 | 1979-01-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-01-06 | 1982-07-08 | 1983-01-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-01-06 | 1986-07-08 | 1987-01-07 | $7700.00 | Window Closed / Lapsed |