Patent US3634196A successfully refreshed from Google Patents.
US3634196A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the separation of pyrogens from crude preparations of l-asparaginase
Assignee: Bayer AG
•
Filing: 1968-12-26
•
Granted: 1972-01-11
•
Expires: 1988-12-26
Abstract
Abstract Crude L-asparaginase is freed of pyrogens by contacting solutions of the same containing weak buffers with diethylaminoethyl dextran gels. The process can be carried out according to batch techniques or in a continuous manner by using a chromatographic column.
Inventors
- 👤 Otto Wagner
- 👤 Klaus Bauer
- 👤 Wilfried Kaufmann
- 👤 Erich Rauenbusch
- 👤 Alfred Arens
- 👤 Eckard Irion
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:46
CPC Classifications
C; C12; C12N; C12N9/00; C12N9/14; C12N9/78; C12N9/80; C12N9/82; Y; Y10; Y10S; Y10S435/00; Y10S435/814; Y10S435/815; Y10S435/8215; Y10S435/822; Y10S435/848; Y10S435/849
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
39 words
The process as defined in claim 1 wherein the contacting of the enzyme solution is carried out by charging a column of the swollen diethylaminoethyl dextran gel and the enzyme fractionated and eluated by buffers of higher salt concentration.
Claim 2
Dependent Claim
45 words
The process as defined in claim 1 wherein the contacting of the enzyme solution is carried out by mixing with the swollen diethylaminoethyl dextran gel, removing the gel from the suspension ad eluating the adsorbed enzyme from the gel with buffers of higher salt coNcentration.
References Cited (Backward Citations)
US3340156A
Cited
US3440142A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-10 | 1975-07-12 | 1976-01-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-10 | 1979-07-12 | 1980-01-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-10 | 1983-07-12 | 1984-01-11 | $7700.00 | Window Closed / Lapsed |