Patent US2886547A successfully refreshed from Google Patents.
Patent US3897309A successfully refreshed from Google Patents.
US3897309A
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Process for removing pyrogenic material from aqueous solutions
Assignee: Merck and Co Inc
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Filing: 1974-02-15
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Granted: 1975-07-29
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Expires: 1994-02-15
Abstract
Abstract Trace amounts of pyrogens are removed from aqueous solutions by passing a strongly ionic solution thereof through a column of a basic anion exchange resin.
Inventors
- 👤 Roy W Grabner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:48
CPC Classifications
C; C12; C12N; C12N9/00; C12N9/14; C12N9/78; C12N9/80; C12N9/82; A; A61; A61K; A61K38/00; A61K38/16; A61K38/43; A61K38/46; A61K38/50; A61P; A61P35/00; Y; Y10; Y10S; Y10S435/00; Y10S435/814; Y10S435/815; Y10S435/8215; Y10S435/822; Y10S435/848; Y10S435/849
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
63 words
A PROCESS FOR THE SEPARATION OF PYROGENIC MATERIAL FROM L-ASPARAGINASE WHICH COMPRISES DISSOLVING SAID ENZYME IN A BUFFER SOLUTION OF IONIC STRENGTH OF FROM 0.1 TO 0.2 M AT A PH OF FROM 7.0 TO 7.5 PASSING THE ENZYME SOLUTION THROUGH A COLUMN OF DIETHYLAMINOETHYL DEXTRAN GEL EQUILIBRATED WITH SAID BUFFER SOLUTION, AND ELUTING THE L-ASPARAGINASE FROM THE COLUMN WITH SAID BUFFER SOLUTION.
Claim 2
Dependent Claim
63 words
A PROCESS FOR THE SEPARATION OF PYROGENIC MATERIAL FROM L-ASPARAGINASE WHICH COMPRISES DISSOLVING SAID ENZYME IN A BUFFER SOLUTION OF IONIC STRENGTH OF FROM 0.1 TO 0.2 M AT A PH OF FROM 7.0 TO 7.5 PASSING THE ENZYME SOLUTION THROUGH A COLUMN OF DIETHYLAMINOETHYL DEXTRAN GEL EQUILIBRATED WITH SAID BUFFER SOLUTION, AND ELUTING THE L-ASPARAGINASE FROM THE COLUMN WITH SAID BUFFER SOLUTION.
Claim 3
Dependent Claim
24 words
A process of claim 1 wherein said buffer solution of high ionic strength is a phosphate buffer solution of from 0.1 to 0.2 m.
Claim 4
Dependent Claim
24 words
A process of claim 2 wherein said buffer solution of high ionic strength is a phosphate buffer solution of from 0.11 to 0.14 m.
Claim 5
Dependent Claim
21 words
A process of claim 3 wherein said buffer solution of high ionic strength is a phosphate buffer solution of 0.12 m.
Claim 6
Dependent Claim
28 words
A process of claim 2 wherein said buffer solution of an ionic strength of from 0.1 to 0.2 is an alkali metal or alkaline earth metal phosphate buffer.
References Cited (Backward Citations)
US2997425A
Cited
US3634196A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-07-28 | 1979-01-27 | 1979-07-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-28 | 1983-01-27 | 1983-07-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-28 | 1987-01-27 | 1987-07-29 | $7700.00 | Window Closed / Lapsed |