US4088748A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hepatitis B surface antigen
Assignee: Merck and Co Inc
•
Filing: 1977-05-04
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Granted: 1978-05-09
•
Expires: 1997-05-04
Abstract
Abstract Biological fluid containing hepatitis B surface antigen is concentrated using ammonium sulfate, and subjected to an isopycnic banding followed by rate zonal banding.
Inventors
- 👤 William J. McAleer
- 👤 Edward H. Wasmuth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 14:17
CPC Classifications
C; C07; C07K; C07K14/00; C07K14/005; C12; C12N; C12N2730/00; C12N2730/00011; C12N2730/10011; C12N2730/10111; C12N2730/10122
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
65 words
A process for obtaining HB s Ag from human biological fluid obtained from human hepatitis B donors comprising treating the fluid with sufficient ammonium sulfate to precipitate an antigen fraction comprising HB s Ag, subjecting the precipitated fraction to an isopycnic banding and to a rate zonal banding, and recovering HB s Ag in the density range of from about 1.13 to about 1.16 g/cc.
Claim 2
Dependent Claim
65 words
A process for obtaining HB s Ag from human biological fluid obtained from human hepatitis B donors comprising treating the fluid with sufficient ammonium sulfate to precipitate an antigen fraction comprising HB s Ag, subjecting the precipitated fraction to an isopycnic banding and to a rate zonal banding, and recovering HB s Ag in the density range of from about 1.13 to about 1.16 g/cc.
Claim 3
Dependent Claim
37 words
A process according to claim 1 wherein the amount of ammonium sulfate is sufficient to precipitate substantially all of the HB s Ag in the fluid but insufficient to precipitate a substantial amount of additional proteinaceous matter.
Claim 4
Dependent Claim
11 words
A process according to claim 1 wherein the fluid is plasma.
Claim 5
Dependent Claim
22 words
A process according to claim 3 wherein the amount of ammonium sulfate is up to about 250 g per liter of plasma.
Claim 6
Dependent Claim
24 words
A process according to claim 3 wherein the amount of ammonium sulfate is from about 200 to about 250 g per liter of plasma.
Claim 7
Dependent Claim
20 words
A process according to claim 3 wherein the amount of ammonium sulfate is about 225 g per liter of plasma.
Claim 8
Dependent Claim
30 words
A process according to claim 1 wherein after addition of ammonium sulfate, the fluid is agitated at from about 0° to about 10° C for at least about 3 hours.
Claim 9
Dependent Claim
30 words
A process according to claim 1 wherein after addition of ammonium sulfate, the fluid is agitated at from about 0° to about 10° C for at least about 4 hours.
Claim 10
Dependent Claim
16 words
A process according to claim 7 wherein the agitation is carried out at about 5° C.
Claim 11
Dependent Claim
13 words
A process according to claim 1 wherein the isopycnic banding gradient is NaBr.
Claim 12
Dependent Claim
14 words
A process according to claim 1 wherein the rate zonal banding gradient is sucrose.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-05-08 | 1981-11-07 | 1982-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-05-08 | 1985-11-07 | 1986-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-05-08 | 1989-11-07 | 1990-05-09 | $7700.00 | Window Closed / Lapsed |