Patent US4416986A successfully refreshed from Google Patents.
US4416986A
Expired / Lapsed
US
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Methods of producing HBsAg
Assignee: Merck and Co Inc
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Filing: 1981-01-16
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Granted: 1983-11-22
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Expires: 2001-01-16
Abstract
Abstract Hepatitis B surface antigen (HBsAg) is produced in vitro in high titer and purity from tissue cultures of cells that shed HBsAg. The cells are grown on hollow fiber capillary units having a molecular weight cut-off of about 10,000.
Inventors
- 👤 Henry Z. Markus
- 👤 William J. McAleer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 22:16
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: 8
Claim 1
Independent Claim
38 words
A method for preparing hepatitis B surface antigen which comprises growing cells which shed hepatitis B surface antigen in the presence of a nutrient medium on hollow fiber capillary units having a molecular weight cut-off of about 10,000.
Claim 2
Independent Claim
38 words
A method for preparing hepatitis B surface antigen which comprises growing cells which shed hepatitis B surface antigen in the presence of a nutrient medium on hollow fiber capillary units having a molecular weight cut-off of about 10,000.
Claim 3
Dependent Claim
33 words
A method according to claim 1 wherein the growing is effected with two sequential stages having differing temperatures, each temperature being above room temperature with the first temperature being above the second temperature.
Claim 4
Dependent Claim
18 words
A method according to claim 2 wherein the first temperature is from about 35° to about 38° C.
Claim 5
Dependent Claim
19 words
A method according to claim 2 wherein the second temperature is from about 30° C. to about 34° C.
Claim 6
Dependent Claim
22 words
A method according to claim 2 wherein the first temperature is about 37° C. and the second temperature is about 32° C.
Claim 7
Dependent Claim
14 words
A method according to claim 2 wherein caffeine is present during the second stage.
Claim 8
Dependent Claim
22 words
A method according to claim 6 wherein the caffeine is present in an amount from about 0.0001 M to about 0.0003 M.
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) | 1986-11-21 | 1987-05-23 | 1987-11-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-11-21 | 1991-05-23 | 1991-11-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-11-21 | 1995-05-23 | 1995-11-22 | $7700.00 | Window Closed / Lapsed |