Patent US4024243A successfully refreshed from Google Patents.
US4024243A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for isolating hepatitis B antigen
Assignee: Merck and Co Inc
•
Filing: 1975-06-16
•
Granted: 1977-05-17
•
Expires: 1995-06-16
Abstract
Abstract An improved process for the preparation of hepatitis B antigen by subjecting plasma of hepatitis B donors to isopycanic banding wherein the step gradient is NaBr. Faster and more economical processing is obtained by multiple loading of the step gradient, either NaBr or conventional gradients.
Inventors
- 👤 William J. McAleer
- 👤 Edward H. Wasmuth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 14:02
CPC Classifications
C; C07; C07K; C07K14/00; C07K14/005; C12; C12N; C12N2730/00; C12N2730/00011; C12N2730/10011; C12N2730/10111; C12N2730/10122; Y; Y10; Y10S; Y10S530/00; Y10S530/827; Y10S530/829; Y10S530/83
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
40 words
In a process for concentrating HB s Ag from clarified plasma of human hepatitis B donors, the improvement comprising subjecting the clarified plasma to isopycnic banding in sodium bromide density gradient and recovering a fraction rich in HB s Ag.
Claim 2
Dependent Claim
40 words
In a process for concentrating HB s Ag from clarified plasma of human hepatitis B donors, the improvement comprising subjecting the clarified plasma to isopycnic banding in sodium bromide density gradient and recovering a fraction rich in HB s Ag.
Claim 3
Dependent Claim
14 words
A process according to claim 1 wherein the density gradient is a step gradient.
Claim 4
Dependent Claim
69 words
In a process for purifying HB s Ag from a plasma that has been subjected to an isopycnic banding in sodium bromide gradient, the improvement comprising subjecting the isopycnic banding fraction having a density region of from about 1.21 g/cc to about 1.24 g/cc to a rate zonal fractionation until the HB s Ag is found in the density region of from about 1.13 g/cc to about 1.16 g/cc.
Claim 5
Dependent Claim
69 words
In a process for purifying HB s Ag from a plasma that has been subjected to an isopycnic banding in sodium bromide gradient, the improvement comprising subjecting the isopycnic banding fraction having a density region of from about 1.21 g/cc to about 1.24 g/cc to a rate zonal fractionation until the HB s Ag is found in the density region of from about 1.13 g/cc to about 1.16 g/cc.
Claim 6
Dependent Claim
44 words
In a process according to claim 1 the improvement comprising subjecting the isopycnic banding product containing HB s Ag to a rate zonal fractionation until the HB s Ag is found in the density region of from about 1.13 g/cc to about 1.16 g/cc.
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) | 1980-05-16 | 1980-11-15 | 1981-05-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-16 | 1984-11-15 | 1985-05-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-16 | 1988-11-15 | 1989-05-17 | $7700.00 | Window Closed / Lapsed |