US4199022A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of freezing living cells and tissues with improved subsequent survival
Assignee: United States Department of Energy
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Filing: 1978-12-08
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Granted: 1980-04-22
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Expires: 1998-12-08
Abstract
Abstract This invention relates to an improved method for freezing red blood cells, other living cells, or tissues with improved subsequent survival, wherein constant-volume freezing is utilized that results in significantly improved survival compared with constant-pressure freezing; optimization is attainable through the use of different vessel geometries, cooling baths and warming baths, and sample concentrations.
Inventors
- 👤 Selim M. Senkan
- 👤 Gerald P. Hirsch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 03:26
CPC Classifications
C; C12; C12N; C12N1/00; C12N1/04; A; A01; A01N; A01N1/00; A01N1/10; A01N1/12; A01N1/122; A01N1/125
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
86 words
A method for increasing survival of living cells taken through a freezing-thawing sequence comprising the steps of placing a sample of said cells in a freezing vessel capable of withstanding rupture when completely filled and sealed; rapidly cooling said filled, sealed vessel to a temperature of about -78° C. at constant volume; and rapidly heating said vessel to a temperature of about 37° C. to thaw said cells, whereby the constant-volume freezing and thawing substantially increase the cell survival compared with conventional constant-pressure freezing and thawing.
Claim 2
Independent Claim
86 words
A method for increasing survival of living cells taken through a freezing-thawing sequence comprising the steps of placing a sample of said cells in a freezing vessel capable of withstanding rupture when completely filled and sealed; rapidly cooling said filled, sealed vessel to a temperature of about -78° C. at constant volume; and rapidly heating said vessel to a temperature of about 37° C. to thaw said cells, whereby the constant-volume freezing and thawing substantially increase the cell survival compared with conventional constant-pressure freezing and thawing.
Claim 3
Dependent Claim
47 words
The method set forth in claim 1, and including between said cooling step and said heating step the further steps of sequentially cooling said vessel to a lower temperature of about -196° C. at constant volume, and heating said vessel to a temperature of about -78° C.
Claim 4
Dependent Claim
14 words
The method set forth in claim 1, wherein said sample is red blood cells.
Claim 5
Dependent Claim
14 words
The method set forth in claim 2, wherein said sample is red blood cells.
Claim 6
Dependent Claim
32 words
The method set forth in claim 1, wherein said sample is a diluted blood cell suspension consisting of 1% fresh blood, 4% citrate glucose solution, and 95% 0.15-M NaCl aqueous solution (V/V).
Claim 7
Dependent Claim
19 words
The method set forth in claim 1, wherein said vessel has a surface-area-to-volume ratio of 4.3 cm -1 .
Claim 8
Dependent Claim
19 words
The method set forth in claim 2, wherein said vessel has a surface-area-to-volume ratio of 4.3 cm -1 .
References Cited (Backward Citations)
US4030314A
Cited
US4117881A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-04-22 | 1983-10-22 | 1984-04-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-04-22 | 1987-10-22 | 1988-04-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-04-22 | 1991-10-22 | 1992-04-22 | $7700.00 | Window Closed / Lapsed |