US3977995A
Expired / Lapsed
US
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Calibrating fluid for blood cell counting and hemoglobin determination
Assignee: Baxter International Inc
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Filing: 1974-10-17
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Granted: 1976-08-31
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Expires: 1994-10-17
Abstract
Abstract A calibrating fluid for automated instruments for blood cell counting and hemoglobin determination comprising a sterile solution of oxyhemoglobin or other derivative products of hemoglobin and containing latex particles.
Inventors
- 👤 Allan L. Louderback
- 👤 Anthony J. Fontana
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:26
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/96; G01N15/00; G01N15/10; G01N15/14; G01N15/1404; G01N2333/00; G01N2333/795; G01N2333/805; G01N2496/00; G01N2496/10; Y; Y10; Y10T; Y10T436/00; Y10T436/10; Y10T436/101666; Y10T436/105831; Y10T436/107497; Y10T436/108331
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
124 words
A calibrating fluid for automated instruments for blood cell counting and hemoglobin determination which is substantially free from red blood cells and which consists essentially of an aqueous isotonic solution containing therein (A) a solubilized material selected from the group consisting of oxyhemoglobin and other hemoglobin derivative products, said solubilized material obtained by completely lysing red blood cells, filtering and recovering the filtrate, and (B) synthetic latex particles selected from the group consisting of polystyrene, polyvinyltoluene, and styrenedivinylbenzene copolymer with a particle size ranging from about 5 to about 20 microns and in an amount of from about 8,000 to about 20,000 particles per cubic millimeter and in which the concentration of (A) as hemoglobin ranges from about 12 gm% to about 20 gm%.
Claim 2
Dependent Claim
124 words
A calibrating fluid for automated instruments for blood cell counting and hemoglobin determination which is substantially free from red blood cells and which consists essentially of an aqueous isotonic solution containing therein (A) a solubilized material selected from the group consisting of oxyhemoglobin and other hemoglobin derivative products, said solubilized material obtained by completely lysing red blood cells, filtering and recovering the filtrate, and (B) synthetic latex particles selected from the group consisting of polystyrene, polyvinyltoluene, and styrenedivinylbenzene copolymer with a particle size ranging from about 5 to about 20 microns and in an amount of from about 8,000 to about 20,000 particles per cubic millimeter and in which the concentration of (A) as hemoglobin ranges from about 12 gm% to about 20 gm%.
Claim 3
Independent Claim
123 words
A method for making a calibrating fluid for automated instruments for blood cell counting and hemoglobin determination comprising: adding about one part of semi-packed blood cells to about three parts of water and stirring for a period of time sufficient to cause complete lysis of the blood cells in the solution; filtering said solution to obtain a filtrate of solubilized material selected from the group consisting of oxyhemoglobin and other hemoglobin derivative products; adding about three parts of said filtrate to about 100 parts of isotonic diluent to form a second solution; adjusting to said third solution a sufficient amount of a solution of synthetic latex particles to provide from about 8,000 to about 22,000 particles of latex per cubic millimeter of solution.
Claim 4
Independent Claim
123 words
A method for making a calibrating fluid for automated instruments for blood cell counting and hemoglobin determination comprising: adding about one part of semi-packed blood cells to about three parts of water and stirring for a period of time sufficient to cause complete lysis of the blood cells in the solution; filtering said solution to obtain a filtrate of solubilized material selected from the group consisting of oxyhemoglobin and other hemoglobin derivative products; adding about three parts of said filtrate to about 100 parts of isotonic diluent to form a second solution; adjusting to said third solution a sufficient amount of a solution of synthetic latex particles to provide from about 8,000 to about 22,000 particles of latex per cubic millimeter of solution.
Claim 5
Dependent Claim
19 words
The process of claim 2 wherein the solution is successively filtered through 1.2, 0.45 and 0.22 micron porous filters.
References Cited (Backward Citations)
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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) | 1979-08-31 | 1980-03-01 | 1980-08-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-08-31 | 1984-03-01 | 1984-08-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-08-31 | 1988-03-01 | 1988-08-31 | $7700.00 | Window Closed / Lapsed |