Patent US3887698A successfully refreshed from Google Patents.
US3887698A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sacs with epitopic sites on walls enclosing stable free radicals
Assignee: Leland Stanford Junior University
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Filing: 1974-02-25
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Granted: 1975-06-03
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Expires: 1994-02-25
Abstract
Abstract A novel immunoassay technique is provided employing sacs having a lysable membrane and at least one determinant or epitopic site recognizable by an antibody. Enclosed in the sacs are water soluble stable free radical compounds, which are capable of escape from the sac upon lysis. The immunoassay can be employed for determination of an epitope containing compound, antibodies or complement. Two basic modes are employed. The first mode depends upon the difference in the EPR spectrum of the stable free radical when enclosed in the sac, at relatively high localized concentration, and when free in solution, at relatively low concentration. The amount of the free radical compound free in solution is dependent upon available antibody bound to the sacs and available complement. The second mode can be used for the determination of an epitope containing compound or antibody. In this mode, the antibody agglutinates the sacs, the agglutinated sacs are separated from the non-agglutinated sacs and either or both of the differentiated sacs lysed and the amount of free radical determined. The immunoassay is extremely sensitive and has a high multiplication factor, because a single event results in the freeing of a large number of free radical molecules.
Inventors
- 👤 Harden M Mcconnell
- 👤 Gillian K Humphries
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:25
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/58; G01N33/585; G01N33/586; G01R; G01R33/00; G01R33/20; G01R33/28; G01R33/281; Y; Y10; Y10S; Y10S436/00; Y10S436/803; Y10S436/815; Y10S436/829
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
69 words
A composition useful in immunoassay comprising vesicles or liposomes having at least one epitopic site on the external walls thereof, said walls enclosing an aqueous medium including stable free radicals comprising electron spin resonance labels, said free radicals being in sufficient concentration to provide an electron paramagnetic resonance spectrum of at least about 3 gauss in half width, peak to peak, at a resonance frequency of about 9.2 gigahertz.
Claim 2
Dependent Claim
69 words
A composition useful in immunoassay comprising vesicles or liposomes having at least one epitopic site on the external walls thereof, said walls enclosing an aqueous medium including stable free radicals comprising electron spin resonance labels, said free radicals being in sufficient concentration to provide an electron paramagnetic resonance spectrum of at least about 3 gauss in half width, peak to peak, at a resonance frequency of about 9.2 gigahertz.
Claim 3
Dependent Claim
69 words
A COMPOSITION USEFUL IN IMMUNOASSAY COMPRISING VESICLES OR LIPOSOMES HAVING AT LEAST ONE EPITOPIC SITE ON THE EXTERNAL WALLS THEREOF, SAID WALLS ENCLOSING AN AQUEOUS MEDIUM INCLUDING STABLE FREE RADICALS COMPRISING ELECTRON SPIN RESONANCE LABELS, SAID FREE RADICALS BEING IN SUFFICIENT CONCENTRATION TO PROVIDE AN ELECTRON PARAMAGNETIC RESONANCE SPECTRUM OF AT LEAST ABOUT 3 GAUSS IN HALF WIDTH, PEAK TO PEAK, AT A RESONANCE FREQUENCY OF ABOUT 9.2 GIGAHERTZ.
Claim 4
Dependent Claim
69 words
A COMPOSITION USEFUL IN IMMUNOASSAY COMPRISING VESICLES OR LIPOSOMES HAVING AT LEAST ONE EPITOPIC SITE ON THE EXTERNAL WALLS THEREOF, SAID WALLS ENCLOSING AN AQUEOUS MEDIUM INCLUDING STABLE FREE RADICALS COMPRISING ELECTRON SPIN RESONANCE LABELS, SAID FREE RADICALS BEING IN SUFFICIENT CONCENTRATION TO PROVIDE AN ELECTRON PARAMAGNETIC RESONANCE SPECTRUM OF AT LEAST ABOUT 3 GAUSS IN HALF WIDTH, PEAK TO PEAK, AT A RESONANCE FREQUENCY OF ABOUT 9.2 GIGAHERTZ.
Claim 5
Dependent Claim
15 words
The composition of claim 1 wherein said epitopic site is covalently bonded to said wall.
Claim 6
Dependent Claim
14 words
The composition of claim 1 wherein said epitopic site is adsorbed on said wall.
Claim 7
Dependent Claim
15 words
The composition of claim 1 wherein said electron spin resonance label is an organic nitroxide.
Claim 8
Dependent Claim
12 words
The composition of claim 4 wherein said wall is a bilayer membrane.
Claim 9
Dependent Claim
11 words
The composition of claim 4 wherein said nitroxide is a salt.
Claim 10
Dependent Claim
12 words
The composition of claim 4 wherein the nitroxide is a neutral molecule.
Claim 11
Dependent Claim
68 words
A composition useful in immunoassay comprising erythrocyte ghosts having at least one epitopic site on the external walls thereof, said walls enclosing an aqueous medium including stable free radicals comprising electron spin resonance labels, said free radicals being in sufficient concentration to provide an electron paramagnetic resonance spectrum of at least about 3 gauss in half width, peak to peak, at a resonance frequency of about 9.2 gigahertz.
Claim 12
Dependent Claim
68 words
A composition useful in immunoassay comprising erythrocyte ghosts having at least one epitopic site on the external walls thereof, said walls enclosing an aqueous medium including stable free radicals comprising electron spin resonance labels, said free radicals being in sufficient concentration to provide an electron paramagnetic resonance spectrum of at least about 3 gauss in half width, peak to peak, at a resonance frequency of about 9.2 gigahertz.
Claim 13
Dependent Claim
67 words
A COMPOSITION USEFUL IN IMMUNOASSAY COMPRISING ERYTHROCYTE GHOSTS HAVING AT LEAST ONE EPITOPIC SITE ON THE EXTERNAL WALLS THEREOF, SAID WALLS ENCLOSING AN AQUEOUS MEDIUM INCLUDING STABLE FREE RADICALS COMPRISING ELECTRON SPIN RESONANCE LABELS, SAID FREE RADICALS COMPRISING ELECTRON SPIN RESONANCE PROVIDE AN ELECTRON PARAMAGNETIC RESONANCE SPECTRUM OF AT LEAST ABOUT 3 GAUSS IN HALF WIDTH, PEAK TO PEAK, AT A RESONANCE FREQUENCY OF ABOUT 9.2 GIGAHERTZ.
Claim 14
Dependent Claim
67 words
A COMPOSITION USEFUL IN IMMUNOASSAY COMPRISING ERYTHROCYTE GHOSTS HAVING AT LEAST ONE EPITOPIC SITE ON THE EXTERNAL WALLS THEREOF, SAID WALLS ENCLOSING AN AQUEOUS MEDIUM INCLUDING STABLE FREE RADICALS COMPRISING ELECTRON SPIN RESONANCE LABELS, SAID FREE RADICALS COMPRISING ELECTRON SPIN RESONANCE PROVIDE AN ELECTRON PARAMAGNETIC RESONANCE SPECTRUM OF AT LEAST ABOUT 3 GAUSS IN HALF WIDTH, PEAK TO PEAK, AT A RESONANCE FREQUENCY OF ABOUT 9.2 GIGAHERTZ.
Claim 15
Dependent Claim
15 words
The composition of claim 8 wherein said epitopic site is covalently bonded to said wall.
Claim 16
Dependent Claim
15 words
The composition of claim 8 wherein said electron spin resonance label is an organic nitroxide.
Claim 17
Dependent Claim
12 words
The composition of claim 10 wherein said organic nitroxide is a salt.
References Cited (Backward Citations)
US3453288A
Cited
US3690834A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-06-02 | 1978-12-02 | 1979-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-02 | 1982-12-02 | 1983-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-02 | 1986-12-02 | 1987-06-03 | $7700.00 | Window Closed / Lapsed |