Fluorescence quenching with immunological pairs in immunoassays
First Claim
1. A method for determining in an assay solution, the presence of a ligand in an unknown suspected of containing said ligand, said ligand having at least one epitopic site, wherein two chromophores, Ch1 and Ch2, which form a fluorescer-quencher pair are employed as reagents, whereby in said assay solution the amount of fluorescer brought within quenching distance of said quencher is affected by the presence of ligand,which comprises:
- A. combining in an aqueous buffered medium to form an assay solution;
1. said unknown;
2. a source of Ch1, as Ch1 covalently bound to a first receptor composition capable of specific non-covalent binding to said ligand;
3. a source of Ch2, as Ch2 covalently bound to a second receptor composition capable of specific non-covalent binding to said ligand or as Ch2 covalently or non-covalently bound to ligand analog, wherein ligand analog is a mono- or polyvalent radical, a substantial proportion of which defines one or more epitopic sites capable of competing with ligand for the binding sites of said receptor;
B. incubating said assay solution for a sufficient time for at least a portion of said receptor compositions to combine with at least a portion of any ligand present;
C. irradiating said incubated assay solution with light at a wavelength within the absorption spectrum of said fluorescer; and
D. measuring the amount of fluorescence from said assay solution as compared to an assay solution having a known amount of ligand.
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Accused Products
Abstract
Immunoassays employing antibodies and a fluorescer-quencher (F-Q) chromophoric pair, wherein one or both of the chromophoric pair are bonded to antibodies. Depending on the particular ligand of interest, various reagent combinations can be employed, where the amount of quenching is directly related to the amount of ligand present in the assay medium. In carrying out the assay, the unknown and antibody specific for the ligand of interest to which is bound one of the F-Q pair, are combined in an aqueous buffered medium. Depending on the protocol, different assay reagents are employed in the aqueous buffered medium: (1) ligand analog bonded to the other of the F-Q pair; (2) antibodies specific for the ligand to which is bound the other of the F-Q pair or; finally, (3) a combination of a plurality of ligands bonded together through linking groups to a hub molecule, usually a polymer, in combination with antibody bound to the other of the F-Q pair. The composition is irradiated with light at a wavelength, absorbed by the fluorescing molecule and the amount of fluorescence determined. By employing appropriate standards, the presence and amount of the ligand can be determined.
1427 Citations
39 Claims
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1. A method for determining in an assay solution, the presence of a ligand in an unknown suspected of containing said ligand, said ligand having at least one epitopic site, wherein two chromophores, Ch1 and Ch2, which form a fluorescer-quencher pair are employed as reagents, whereby in said assay solution the amount of fluorescer brought within quenching distance of said quencher is affected by the presence of ligand,
which comprises: -
A. combining in an aqueous buffered medium to form an assay solution; 1. said unknown; 2. a source of Ch1, as Ch1 covalently bound to a first receptor composition capable of specific non-covalent binding to said ligand; 3. a source of Ch2, as Ch2 covalently bound to a second receptor composition capable of specific non-covalent binding to said ligand or as Ch2 covalently or non-covalently bound to ligand analog, wherein ligand analog is a mono- or polyvalent radical, a substantial proportion of which defines one or more epitopic sites capable of competing with ligand for the binding sites of said receptor; B. incubating said assay solution for a sufficient time for at least a portion of said receptor compositions to combine with at least a portion of any ligand present; C. irradiating said incubated assay solution with light at a wavelength within the absorption spectrum of said fluorescer; and D. measuring the amount of fluorescence from said assay solution as compared to an assay solution having a known amount of ligand. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A method for determining in an assay solution, the presence of a ligand in an unknown suspected of containing said ligand, said ligand having one or more epitopic sites;
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in which is employed two chromophores, Ch1 and Ch2, which form a fluorescer-quencher pair, one of the chromophores, Ch1, is bound to receptor for ligand to form receptor-Ch1, said receptor having binding sites capable of specifically binding to the epitopic sites of said ligand, the other of the chromophores, Ch2 is bound to receptor for ligand to form receptor-Ch2 or to ligand analog, either a single ligand analog being covalently bound to one or more chromophores to form ligand analog-(Ch2)x, where x is on the average at least one, or a plurality of ligand analogs and chromophores being covalently bound to a polyfunctionalized nucleus molecule to form poly(ligand analog)-poly(Ch2), wherein ligand analog is a mono- or polyvalent radical, a substantial proportion of which defines one or more epitopic sites capable of competing with ligand for the binding sites of said receptor; and wherein the amount of fluorescer within quenching distance of quencher is related to the amount of ligand present in said assay solution; which comprises; A. combining in an aqueous buffered medium to form an assay solution; - View Dependent Claims (22, 23, 24, 26, 27, 29, 31, 34)
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21. unknown;
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2. receptor-Ch1 ; and 3. a source of Ch2 capable of binding within quenching distance to receptor-Ch2, as one of the following; a. ligand analog-(Ch2)x ; b. poly(ligand analog)-poly(Ch2); c. poly(ligand analog) and receptor-Ch2 ; wherein poly(ligand analog) has a plurality of ligand analogs covalently bound to a polyfunctionalized nucleus molecule;
orwhen said ligand has a plurality of epitopic sites, d. receptor-Ch2 ; B. incubating said assay solution for a sufficient time for at least a portion of the receptor present to combine with at least a portion of any ligand present; C. irradiating said incubated assay solution with light at a wavelength within the absorption spectrum of said fluorescer; and D. measuring the amount of fluorescence from said assay solution as compared to an assay solution having a known amount of ligand.
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25. A method for determining in an assay solution, the presence of a ligand in an unknown suspected of containing said ligand, said ligand having one epitopic site,
in which is employed two chromophores, Ch1 and Ch2, which form a fluorescer-quencher pair, one of the chromophores, Ch1 is bound to receptor for ligand to form receptor-Ch1, said receptor having a binding site capable of specifically binding to the epitopic site of said ligand, the other of the chromophores is covalently bound to ligand analog to form ligand analog-Ch2, wherein ligand analog is a monovalent radical, a substantial proportion of which defines an epitopic site capable of competing with ligand for a binding site of said receptor; - and
wherein the amount of fluorescer within quenching distance of quencher is related to the amount of ligand present in said assay solution; which comprises; A. combining in an aqueous buffered medium at a pH in the range of about 5 to 10 to form an assay solution; 1. unknown; 2. receptor-Ch1 ; 3. ligand analog-Ch2 ; the concentrations of receptor-Ch1 and ligand analog-Ch2 providing from about 20 to 80% quenching of the fluorescence in the absence of ligand; B. incubating said assay solution at a temperature in the range of about 0-45°
C for a sufficient time for at least a portion of the receptor present to combine with at least a portion of any ligand present;C. irradiating said incubated assay solution with light at a wavelength within the absorption spectrum of said fluorescer; and D. measuring the amount of fluorescence from said assay solution as compared to an assay solution having a known amount of ligand.
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28. A method for determining in an assay solution, the presence of a ligand in an unknown suspected of containing said ligand, said ligand having a plurality of epitopic sites,
in which is employed two chromophores, Ch1 and Ch2, which form a fluorescer-quencher pair, one of the chromophores, Ch1, is bound to receptor for ligand to form receptor-Ch1, said receptor having binding sites capable of specifically binding to the epitopic sites of said ligand, the other of the chromophores is bound to receptor for ligand to form receptor-Ch2 ; -
wherein the amount of fluorescer within quenching distance of quencher is related to the amount of ligand present in said assay solution; which comprises; A. combining in an aqueous buffered medium at a pH in the range of about 5 to 10, to form an assay solution; 1. unknown; 2. receptor-Ch1 ; 3. receptor-Ch2 ; B. incubating said assay solution at a temperature in the range of about 0°
-45°
C for a sufficient time for at least a portion of the receptor present to combine with at least a portion of any ligand present;C. irradiating said incubated assay solution with light at a wavelength within the absorption spectrum of said fluorescer; and D. measuring the amount of fluorescence from said assay solution as compared to an assay solution having a known amount of ligand.
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30. A method for determining in an assay solution, the presence of a ligand in an unknown suspected of containing said ligand, said ligand having one or more epitopic sites,
in which is employed two chromophores, Ch1 and Ch2, which form a fluorescer-quencher pair, one of the chromophores, Ch1, is bound to receptor for ligand to form receptor-Ch1, said receptor having binding sites capable of specifically binding to the epitopic sites of said ligand, the other of the chromophores is bound to receptor for ligand to form receptor-Ch2 ; -
wherein the amount of fluorescer within quenching distance of quencher is related to the amount of ligand present in said assay solution; which comprises; A. combining in an aqueous buffered medium at a pH in the range of 5 to 10 to form an assay solution; 1. unknown; 2. receptor-Ch1 ; 3. poly(ligand analog) and receptor-Ch2, wherein ligand analog is a mono- or polyvalent radical, a substantial proportion of which defines one or more epitopic sites capable of competing with ligand for the binding sites of said receptor and poly(ligand analog) has a plurality of ligand analogs covalently bound to a polyfunctionalized nucleus molecule; B. incubating said assay solution at a temperature in the range of about 0-45°
C for a sufficient time for at least a portion of the receptor present to combine with at least a portion of any ligand present;C. irradiating said incubated assay solution with light at a wavelength within the absorption spectrum of said fluorescer; and D. measuring the amount of fluorescence from said assay solution as compared to an assay solution having a known amount of ligand. - View Dependent Claims (32, 33)
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35. A method for determining in an assay solution the presence of a ligand or anti-ligand in an unknown suspected of containing said ligand or anti-ligand, said ligand and anti-ligand having a plurality of epitopic sites;
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in which is employed anti(anti-ligand), a portion of which is bound to Ch1 and a portion of which is bound to Ch2, wherein Ch1 and Ch2 form a fluorescer-quencher pair; combining with said unknown (1) anti-ligand for the determination of the presence of ligand, or (2) ligand for the determination of the presence of anti-ligand; separating anti-ligand bound to ligand from unbound anti-ligand; combining in an aqueous buffered assay solution said bound anti-ligand with said anti(anti-ligand)s; irradiating said assay solution with light at a wavelength within the absorption spectrum of said fluorescer; and measuring the amount of fluorescence from said assay solution as compared to an assay solution having a known amount of ligand or anti-ligand.
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36. A method for determining in an assay solution the presence of a ligand in an unknown suspected of containing said ligand, said ligand having a plurality of epitopic sites, in which method is employed a-(anti-ligand), b-(anti-ligand), anti(a-(anti-ligand)-Ch1 and anti(b-(anti-ligand)-Ch2, wherein a and b designate a different species source for the anti-ligand and Ch1 and Ch2 form a fluorescer-quencher pair, wherein the amount of fluorescer within quenching distance of quencher is related to the amount of ligand present in said assay solution,
which comprises: -
A. combining in an aqueous buffered medium to form an assay solution; 1. unknown; 2. a-(anti-ligand); 3. b-(anti-ligand); 4. anti(a-(anti-ligand)-Ch1 ; and 5. anti(b-(anti-ligand)-Ch2 ; B. incubating said assay solution for a sufficient time for at least a portion of the anti-ligands and anti(anti-ligand)s to combine with ligand and anti-ligand respectively; C. irradiating said incubated assay solution with light at a wavelength within the absorption spectrum of said fluorescer; and D. measuring the amount of fluorescence from said assay solution as compared to an assay solution having a known amount of ligand.
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37. A method for determining in an assay solution, the presence of anti-ligand for a ligand in an unknown suspected of containing said anti-ligand,
in said method is employed (anti-ligand)-Ch1 and (anti-ligand)-Ch2, wherein Ch1 and Ch2 form a fluorescer-quencher pair; -
wherein anti-ligand present in the unknown diminishes the amount of quenching of said fluorescer by said quencher; and which comprises; combining in an aqueous buffered assay medium; 1. said unknown; 2. said ligand, when said ligand is polyepitopic, or poly(ligand analog) when said ligand is monoepitopic; 3. (anti-ligand)-Ch1 ; and 4. (anti-ligand)-Ch2 ; irradiating said assay solution with light at a wavelength within the absorption spectrum of said fluorescer; and measuring the amount of fluorescence from said assay solution as compared to an assay solution having a known amount of anti-ligand. - View Dependent Claims (39)
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38. In combination, anti(a-anti-ligand)-Ch1 and anti(b-anti-ligand)-Ch2 wherein a and b designate anti-ligand from two different species for the same ligand, said ligand having a plurality of epitopic sites, and Ch1 and Ch2 designate a fluorescer-quencher pair.
Specification