US4139440A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrofocusing in buffers
Assignee: Government of the United States of America
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Filing: 1977-06-20
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Granted: 1979-02-13
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Expires: 1997-06-20
Abstract
Abstract Methods of electrofocusing in amphoteric or non-amphoteric buffers is disclosed. In such methods, buffers are employed as carrier constituents, and optionally as anolyte and catholyte. Using a buffer electrofocusing system, stability with time has been achieved for a natural pH gradient.
Inventors
- 👤 Andreas Chrambach
- 👤 Nga Y. Nguyen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 12:26
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/26; G01N27/416; G01N27/447; G01N27/44756; G01N27/44795; G01N27/44704; G01N27/44747
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
70 words
In a method of isoelectric focusing between acid anolyte and basic catholyte, the improvement which comprises forming a pH gradient in a mixture of a plurality of buffers located in the field between said anolyte and said catholyte, wherein the a acid anolyte and basic catholyte are replaced by the leading and trailing buffers of the buffer mixture, possessing the lowest and highest pK 2 values of the buffer mixture.
Claim 2
Dependent Claim
70 words
In a method of isoelectric focusing between acid anolyte and basic catholyte, the improvement which comprises forming a pH gradient in a mixture of a plurality of buffers located in the field between said anolyte and said catholyte, wherein the a acid anolyte and basic catholyte are replaced by the leading and trailing buffers of the buffer mixture, possessing the lowest and highest pK 2 values of the buffer mixture.
Claim 3
Dependent Claim
16 words
The method of claim 1, wherein the buffer anolyte and catholyte are made 50% in sucrose.
Claim 4
Dependent Claim
19 words
The method of claim 1, wherein the buffer anolyte and catholyte are present in a concentration of 0.75 M.
Claim 5
Dependent Claim
61 words
In a method of isoelectric focusing between acid anolyte and basic catholyte, the improvement which comprises forming a pH gradient in a mixture of a plurality of buffers located in the field between said anolyte and said catholyte, wherein the acid anolyte and basic catholyte are replaced by isoelectric buffers identical to the terminal constituents of the pH gradient and gel.
Claim 6
Dependent Claim
61 words
In a method of isoelectric focusing between acid anolyte and basic catholyte, the improvement which comprises forming a pH gradient in a mixture of a plurality of buffers located in the field between said anolyte and said catholyte, wherein the acid anolyte and basic catholyte are replaced by isoelectric buffers identical to the terminal constituents of the pH gradient and gel.
Claim 7
Dependent Claim
60 words
In a method of isoelectric focusing between acid anolyte and basic catholyte, the improvement which comprises forming a pH gradient in a mixture of a plurality of buffers located in the field between said anolyte and said catholyte, wherein the pH of the anolyte is equalized with the pH of the most acidic pI of the selected continuous pI range.
Claim 8
Dependent Claim
60 words
In a method of isoelectric focusing between acid anolyte and basic catholyte, the improvement which comprises forming a pH gradient in a mixture of a plurality of buffers located in the field between said anolyte and said catholyte, wherein the pH of the anolyte is equalized with the pH of the most acidic pI of the selected continuous pI range.
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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) | 1982-02-12 | 1982-08-14 | 1983-02-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-02-12 | 1986-08-14 | 1987-02-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-02-12 | 1990-08-14 | 1991-02-13 | $7700.00 | Window Closed / Lapsed |