US4250051A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preservative for use in calibrator compositions for blood analysis
Assignee: Coulter Electronics Inc
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Filing: 1978-12-26
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Granted: 1981-02-10
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Expires: 1998-12-26
Abstract
Abstract A stable calibrator composition, useful in equipment for determining hematological values in blood samples, comprises a hemolysate of red blood cells which have been lysed with a dilute aqueous solution of saponin to which has been added a halophenol that has a phenol coefficient of between 20 and 90 to provide a concentration from about 1:1000 to about 1:1750 w/v of said halophenol in said hemolysate, said calibrator composition having a pH between 4 and 7. The preferred halophenol is 4-chloro-3,5-xylenol.
Inventors
- 👤 Douglas Armstrong
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 15:50
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/96; G01N15/00; G01N15/10; G01N2333/00; G01N2333/795; G01N2333/805; G01N2496/00; G01N2496/05; Y; Y10; Y10T; Y10T436/00; Y10T436/10; Y10T436/105831; Y10T436/107497; Y10T436/108331
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
69 words
A stable calibrator composition, useful for calibrating instruments which determine hematological values in whole blood samples, comprising a mixture of (a) a hemolysate of red blood cells which have been lysed with an aqueous solution of saponin, and (b) a preservative amount of 4-chloro-3,5-xylenol, the concentration of said 4-chloro-3,5-xylenol in said hemolysate being from about 1:1000 to 1:1750 w/v, and said hemolysate having a pH between 4 and 7.
Claim 2
Dependent Claim
69 words
A stable calibrator composition, useful for calibrating instruments which determine hematological values in whole blood samples, comprising a mixture of (a) a hemolysate of red blood cells which have been lysed with an aqueous solution of saponin, and (b) a preservative amount of 4-chloro-3,5-xylenol, the concentration of said 4-chloro-3,5-xylenol in said hemolysate being from about 1:1000 to 1:1750 w/v, and said hemolysate having a pH between 4 and 7.
Claim 3
Dependent Claim
34 words
The composition according to claim 1 to which is added a calculated amount of aldehyde fixed red blood cells, sufficient to substitute for the white blood cells which are normally found in whole blood.
Claim 4
Dependent Claim
80 words
A process for the preparation of a stable composition useful for calibrating instruments which determine hematological values including white cell count in blood samples which comprises the steps of: (a) lysing the red blood cells by agitating with an aqueous solution of saponin to form a hemolysate having a pH between 4 and 7; and (b) adding to said hemolysate a preservative amount of 4-chloro-3,5-xylenol, the concentration of said 4-chloro-3,5-xylenol in said hemolysate being from about 1:1000 to 1:1750 w/v.
Claim 5
Dependent Claim
80 words
A process for the preparation of a stable composition useful for calibrating instruments which determine hematological values including white cell count in blood samples which comprises the steps of: (a) lysing the red blood cells by agitating with an aqueous solution of saponin to form a hemolysate having a pH between 4 and 7; and (b) adding to said hemolysate a preservative amount of 4-chloro-3,5-xylenol, the concentration of said 4-chloro-3,5-xylenol in said hemolysate being from about 1:1000 to 1:1750 w/v.
Claim 6
Dependent Claim
38 words
The method of claim 3 wherein a calculated amount of aldehyde fixed red blood cells, sufficient to substitute for the white blood cells which are normally found in whole blood is added to said hemolysate in step (b).
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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) | 1984-02-10 | 1984-08-11 | 1985-02-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-02-10 | 1988-08-11 | 1989-02-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-02-10 | 1992-08-11 | 1993-02-10 | $7700.00 | Window Closed / Lapsed |