US4806466A
Expired / Lapsed
US
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Cell agglutination reagent comprising conjugates of antibody covalently bound to liposomes
Assignee: University of California, San Diego
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Filing: 1986-03-17
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Granted: 1989-02-21
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Expires: 2006-03-17
Abstract
Abstract A number of naturally occurring antibodies to human erythrocyte surface antigens are capable of combining with their specific antigens (for example, Rhesus factor), but are not capable of producing visible hemagglutination. Also, the sensitivity of many diagnostic methods, such as in human blood typing, depends upon cell agglutination. The present invention provides liposome-protein conjugates, especially useful for hemagglutination assays, having an enhanced agglutination capacity with respect to antibody from which the conjugates are derived.
Inventors
- 👤 Demetrios P. Papahadjopoulos
- 👤 Timothy D. Heath
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 01:37
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/53; G01N33/543; G01N33/554; G01N33/80; Y; Y10; Y10S; Y10S436/00; Y10S436/829
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
95 words
A reagent, useful for hemagglutination assays, comprising: conjugates comprising (a) liposomes and (b) antibody covalently bound to the liposomes, the liposomes having lipid molecules, the covalently bound antibody having an antigen binding capacity for erythrocytes, said erythrocytes bearing a surface antigen for which the covalently bound antibody is specific, to mediate hemagglutination via antigen-antibody interaction, the covalently bound antibody being in an amount of at least about 40 micrograms per micromole of lipid molecules, the conjugates having an enhanced hemagglutinating activity with respect to the hemagglutinating activity of antibody from which the conjugates are derived.
Claim 2
Dependent Claim
95 words
A reagent, useful for hemagglutination assays, comprising: conjugates comprising (a) liposomes and (b) antibody covalently bound to the liposomes, the liposomes having lipid molecules, the covalently bound antibody having an antigen binding capacity for erythrocytes, said erythrocytes bearing a surface antigen for which the covalently bound antibody is specific, to mediate hemagglutination via antigen-antibody interaction, the covalently bound antibody being in an amount of at least about 40 micrograms per micromole of lipid molecules, the conjugates having an enhanced hemagglutinating activity with respect to the hemagglutinating activity of antibody from which the conjugates are derived.
Claim 3
Dependent Claim
32 words
The reagent of claim 1 wherein: the covalently bound antibody is derived from a polyclonal antiserum or is a monoclonal antibody, and the hemagglutinating activity is determinable as a minimum hemagglutinating concentration.
Claim 4
Dependent Claim
30 words
The reagent as in claim 1 wherein: the enhanced hemagglutinating activity is at least about 1.5 times greater than the hemagglutinating activity of antibody from which the conjugates are derived.
Claim 5
Dependent Claim
23 words
The reagent as in claim 1 wherein: the liposomes of the conjugates are from about 0.1 micron to about 5 micron in size.
Claim 6
Dependent Claim
21 words
The reagent as in claim 1 wherein: the liposomes are a substantially uniform size between about 0.1 and about 0.5 microns.
Claim 7
Dependent Claim
17 words
The reagent as in claim 1 wherein: the covalently bound antibody is IgG or a fragment thereof.
Claim 8
Dependent Claim
30 words
The reagent as in claim 6 wherein: the IgG or fragment thereof is in an amount of from about 40 micrograms to about 90 micrograms per micromole of lipid molecule.
Claim 9
Dependent Claim
97 words
A reagent, useful for cell agglutination assays, comprising: conjugates comprising (a) liposomes and (b) antibody covalently bound to the liposomes, the liposomes having lipid molecules, the covalently bound antibody having an antigen binding capacity for cells, said cells bearing a cell surface antigen for which the covalently bound antibody is specific, to mediate agglutination via antigen-antibody interaction, the covalently bound antibody being in an amount of at least about 40 micrograms per micromole of lipid molecules, the conjugates having an enhanced agglutinating activity with respect to the agglutinating activity of antibody from which the conjugates are derived.
Claim 10
Dependent Claim
97 words
A reagent, useful for cell agglutination assays, comprising: conjugates comprising (a) liposomes and (b) antibody covalently bound to the liposomes, the liposomes having lipid molecules, the covalently bound antibody having an antigen binding capacity for cells, said cells bearing a cell surface antigen for which the covalently bound antibody is specific, to mediate agglutination via antigen-antibody interaction, the covalently bound antibody being in an amount of at least about 40 micrograms per micromole of lipid molecules, the conjugates having an enhanced agglutinating activity with respect to the agglutinating activity of antibody from which the conjugates are derived.
Claim 11
Dependent Claim
21 words
The reagent of claim 8 wherein: the covalently bound antibody is derived from a polyclonal antiserum or is a monoclonal antibody.
Claim 12
Dependent Claim
23 words
The reagent as in claim 8 wherein: the liposomes of the conjugates are from about 0.1 micron to about 5 microns in size.
Claim 13
Dependent Claim
21 words
The reagent as in claim 8 wherein: the liposomes are a substantially uniform size between about 0.1 and about 0.5 microns.
Claim 14
Dependent Claim
17 words
The reagent as in claim 8 wherein: the covalently bound antibody is IgG or a fragment thereof.
Claim 15
Dependent Claim
13 words
The reagent as in claim 8 wherein the cells include fibroblasts or lymphocytes.
Claim 16
Dependent Claim
29 words
The reagent as in claim 8 wherein the covalently bound antibody includes IgG or Fab fragments which are attached to the lipid molecules of the liposomes through disulfide bonds.
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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) | 1992-02-21 | 1992-08-22 | 1993-02-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-02-21 | 1996-08-22 | 1997-02-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-02-21 | 2000-08-22 | 2001-02-21 | $7700.00 | Window Closed / Lapsed |