Patent US4622302A successfully refreshed from Google Patents.
US4622302A
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Process for inducing membrane fusion under an electric field
Assignee: American Red Cross
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Filing: 1984-08-09
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Granted: 1986-11-11
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Expires: 2004-08-09
Abstract
Abstract A device and process for inducing membrane fusion under an electric field. The process comprises the steps of (a) suspending said membranes in an aqueous buffered medium in a manner so that the membranes are without contact with each other; (b) altering said membranes to a fusogenic state by applying 2-30 pulses of direct current at a rate of 2 to 5 pulses per second in an electrical field strength of about 500-1000 volts/mm in the medium, said pulses having a rapid rise time not exceeding about 10 micro seconds and an exponential decay half time of about 0.2 milliseconds to about 1.2 milliseconds; and (c) thereafter bringing said fusogenic membranes in contact with each other. A long-lived metastable fusogenic state of membranes can be obtained by the device and process.
Inventors
- 👤 Arthur E. Sowers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 11:07
CPC Classifications
C; C12; C12N; C12N13/00; C12M; C12M35/00; C12M35/02; Y; Y10; Y10S; Y10S204/00; Y10S204/08; Y10S204/09
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
106 words
A process for inducing fusion of cell membranes comprising the sequential steps of (a) suspending cell membranes in an aqueous buffered medium so that the membranes are without contact with each other; (b) altering said membranes to a fusogenic state by applying 2-30 pulses of direct current at a rate of 2 to 5 pulses per second in an electrical field strength of about 500-1000 volts/mm in the medium, said pulses having a rise time not exceeding about 10 microseconds and an exponential decay half time of about 0.2 milliseconds to about 1.2 milliseconds; and (c) thereafter bringing said fusogenic membranes in contact with each other.
Claim 2
Dependent Claim
106 words
A process for inducing fusion of cell membranes comprising the sequential steps of (a) suspending cell membranes in an aqueous buffered medium so that the membranes are without contact with each other; (b) altering said membranes to a fusogenic state by applying 2-30 pulses of direct current at a rate of 2 to 5 pulses per second in an electrical field strength of about 500-1000 volts/mm in the medium, said pulses having a rise time not exceeding about 10 microseconds and an exponential decay half time of about 0.2 milliseconds to about 1.2 milliseconds; and (c) thereafter bringing said fusogenic membranes in contact with each other.
Claim 3
Dependent Claim
18 words
The process of claim 1 wherein step (c) commences after an interval of time subsequent to step (b).
Claim 4
Dependent Claim
13 words
The process of claim 1 wherein step (c) commences immediately after step (b).
Claim 5
Dependent Claim
18 words
The process of claim 1 wherein said buffered medium has a buffer concentration ranging from about 20-150 mM.
Claim 6
Dependent Claim
18 words
The process of claim 4 wherein said buffered medium has a pH value of about 4 to 10.
Claim 7
Dependent Claim
19 words
The process of claim 1 wherein the step of bringing said fusogenic membranes in contact comprises applying alternating current.
Claim 8
Dependent Claim
20 words
The process of claim 6 wherein said alternating current has a frequency range of about 40 Hz to 10 KHz.
Claim 9
Dependent Claim
21 words
The process of claim 7 wherein said alternating current has an electric field strength in the range of about 7-25 volts/mm.
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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) | 1989-11-10 | 1990-05-12 | 1990-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-11-10 | 1994-05-12 | 1994-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-11-10 | 1998-05-12 | 1998-11-11 | $7700.00 | Window Closed / Lapsed |