US4315852A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Extraction of interferon from bacteria
Assignee: Merck Sharp & Dohme LLC
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Filing: 1980-12-29
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Granted: 1982-02-16
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Expires: 2000-12-29
Abstract
Abstract A method of extracting leucocyte interferon from interferon-expressing bacterial cells comprising acidifying a suspension of interferon-containing bacterial cells, removing substantially all of the suspension liquid from the cells, preparing a second suspension of the acidified cells, neutralizing said second suspension, separating the interferon containing liquid from the suspended cells, and extracting the interferon from said liquid.
Inventors
- 👤 Paul Leibowitz
- 👤 Marvin J. Weinstein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:49
CPC Classifications
C; C07; C07K; C07K14/00; C07K14/435; C07K14/52; C07K14/555; C07K14/56; C12; C12N; C12N1/00; C12N1/005; Y; Y10; Y10S; Y10S435/00; Y10S435/811; Y10S530/00; Y10S530/82; Y10S530/825
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
56 words
A method of extracting leucocyte interferon from interferon-expressing bacterial cells comprising acidifying a suspension of interferon-containing bacterial cells, removing substantially all of the suspension liquid from the cells, preparing a second suspension of the acidified cells, neutralizing said second suspension, separating the interferon containing liquid from the suspended cells, and extracting the interferon from said liquid.
Claim 2
Independent Claim
56 words
A method of extracting leucocyte interferon from interferon-expressing bacterial cells comprising acidifying a suspension of interferon-containing bacterial cells, removing substantially all of the suspension liquid from the cells, preparing a second suspension of the acidified cells, neutralizing said second suspension, separating the interferon containing liquid from the suspended cells, and extracting the interferon from said liquid.
Claim 3
Dependent Claim
17 words
A method according to claim 1, wherein said suspension is acidified with sulfuric acid or phosphoric acid.
Claim 4
Dependent Claim
19 words
A method according to claim 1, wherein said suspension is acidified to a pH of about 1.3 to 4.0.
Claim 5
Dependent Claim
19 words
A method according to claim 1, wherein said suspension is acidified to a pH of about 2.0 to 2.5.
Claim 6
Dependent Claim
18 words
A method according to claim 1, wherein said second suspension is neutralized with potassium hydroxide or sodium hydroxide.
Claim 7
Dependent Claim
20 words
A method according to claim 1, wherein said second suspension is neutralized to a pH of about 7.0 to 8.0.
Claim 8
Dependent Claim
20 words
A method according to claim 1, wherein said second suspension is neutralized to a pH of about 7.2 to 7.6.
Claim 9
Dependent Claim
12 words
A method according to claim 1, wherein said bacteria is E. coli.
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) | 1985-02-15 | 1985-08-17 | 1986-02-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-02-15 | 1989-08-17 | 1990-02-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-02-15 | 1993-08-17 | 1994-02-16 | $7700.00 | Window Closed / Lapsed |