Patent US5472881A successfully refreshed from Google Patents.
US5472881A
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Thiol labeling of DNA for attachment to gold surfaces
Assignee: University of Utah
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Filing: 1994-03-21
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Granted: 1995-12-05
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Expires: 2014-03-21
Abstract
Abstract A method for adsorbing nucleic acids to a surface of a gold substrate for analyzing the structure of the nucleic acid includes the steps of thiolating the nucleic acid by substituting at least one non-bridging internucleotide oxygen of each phosphodiester moiety with sulfur, depositing the thiolated nucleic acid on the gold surface, and subjecting the nucleic acid to analysis for determining the atomic or molecular structure thereof. The gold surface is prepared by subjecting a gold single crystal to mechanical polishing, electropolishing, cleaning by cycles of Ar + sputtering and annealing under vacuum until no contamination is detected by Auger electron spectroscopy, and flame annealing and quenching in methanol. Gold films deposited on atomically flat substrates, such as mica, can also be used. The thiolated DNA is deposited on the gold surface for a sufficient time for covalent bonds to form between the sulfur and the gold. Scanning tunneling microscopy, atomic force microscopy, angle-dependent x-ray photoelectron spectroscopy, and Auger electron spectroscopy are used to analyze the nucleic acid structure.
Inventors
- 👤 Thomas P. Beebe
- 👤 Carol E. Rabke-Clemmer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 07:24
CPC Classifications
C; C12; C12Q; C12Q1/00; C12Q1/68; C12Q1/6813; C12Q1/6834; B; B82; B82Y; B82Y15/00; G; G01; G01N; G01N23/00; G01N23/22; G01N23/227; G01N23/2273; Y; Y10; Y10T; Y10T436/00; Y10T436/14; Y10T436/142222; Y10T436/143333
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
111 words
A method for immobilizing a nucleic acid, containing phosphodiester and base moieties, to a surface of a gold substrate so that the base moieties are exposed and unreacted, comprising the steps of: (a) thiolating the nucleic acid by substituting at least one non-bridging internucleotide oxygen atom of each phosphodiester moiety in the nucleic acid with a sulfur atom; and (b) depositing the thiolated nucleic acid on the surface of the gold substrate under conditions such that a covalent bond is formed between each sulfur atom and the gold at the surface of the substrate thereby immobilizing the nucleic acid while leaving the base moieties of the nucleic acid exposed and unreacted.
Claim 2
Independent Claim
111 words
A method for immobilizing a nucleic acid, containing phosphodiester and base moieties, to a surface of a gold substrate so that the base moieties are exposed and unreacted, comprising the steps of: (a) thiolating the nucleic acid by substituting at least one non-bridging internucleotide oxygen atom of each phosphodiester moiety in the nucleic acid with a sulfur atom; and (b) depositing the thiolated nucleic acid on the surface of the gold substrate under conditions such that a covalent bond is formed between each sulfur atom and the gold at the surface of the substrate thereby immobilizing the nucleic acid while leaving the base moieties of the nucleic acid exposed and unreacted.
Claim 3
Dependent Claim
15 words
The method as in claim 1 wherein the gold substrate comprises a gold single crystal.
Claim 4
Dependent Claim
16 words
The method as in claim 2 wherein the gold substrate comprises a single crystal of Au(111).
Claim 5
Dependent Claim
28 words
The method as in claim 2 wherein, as a preparatory step, the single gold crystal is polished and cleaned until no contamination is detected by Auger electron spectroscopy.
Claim 6
Dependent Claim
45 words
The method as in claim 4 wherein the single gold crystal is polished and cleaned by the following sequential steps: (a) mechanical polishing; (b) electropolishing; (c) cleaning under vacuum by cycles of Ar + sputtering and annealing; and (d) flame annealing and quenching in methanol.
Claim 7
Dependent Claim
12 words
The method as in claim 2 wherein the nucleic acid is DNA.
Claim 8
Dependent Claim
12 words
The method as in claim 2 wherein the nucleic acid is RNA.
Claim 9
Dependent Claim
14 words
The method as in claim 1 wherein the gold substrate comprises a gold film.
Claim 10
Dependent Claim
70 words
The method as in claim 1 wherein step (b) comprises placing a solution of the thiolated nucleic acid on the surface of the gold substrate and permitting the thiolated nucleic acid solution and gold substrate to incubate together for a sufficient time for a soft acid/soft base reaction to occur between each sulfur atom and the gold such that covalent bonds are formed between each sulfur atom and the gold.
Claim 11
Dependent Claim
24 words
The method as in claim 9 wherein the thiolated nucleic acid solution and the gold substrate incubate together for a minimum of 10 hours.
Claim 12
Independent Claim
132 words
A method for analyzing the structure of a nucleic acid, containing phosphodiester and base moieties, immobilized on the surface of a gold substrate so that the base moieties are exposed and unreacted, comprising the steps of: (a) thiolating a nucleic acid by substituting at least one non-bridging internucleotide oxygen atom of each phosphodiester moiety of the nucleic acid with a sulfur atom; (b) depositing the thiolated nucleic acid on the surface of the gold substrate under conditions such that a covalent bond is formed between each sulfur atom and the gold at the surface of the substrate thereby immobilizing the nucleic acid while leaving the base moieties of the nucleic acid exposed and unreacted; and (c) subjecting the immobilized nucleic acid to analysis means and determining the atomic or molecular structure thereof.
Claim 13
Independent Claim
132 words
A method for analyzing the structure of a nucleic acid, containing phosphodiester and base moieties, immobilized on the surface of a gold substrate so that the base moieties are exposed and unreacted, comprising the steps of: (a) thiolating a nucleic acid by substituting at least one non-bridging internucleotide oxygen atom of each phosphodiester moiety of the nucleic acid with a sulfur atom; (b) depositing the thiolated nucleic acid on the surface of the gold substrate under conditions such that a covalent bond is formed between each sulfur atom and the gold at the surface of the substrate thereby immobilizing the nucleic acid while leaving the base moieties of the nucleic acid exposed and unreacted; and (c) subjecting the immobilized nucleic acid to analysis means and determining the atomic or molecular structure thereof.
Claim 14
Dependent Claim
34 words
The method as in claim 11 wherein the analysis means of step (c) is selected from the group consisting of scanning tunneling microscopy, atomic force microscopy, angle-dependent x-ray photoelectron spectroscopy, and Auger electron spectroscopy.
Claim 15
Dependent Claim
14 words
The method as in claim 12 wherein the analysis means is scanning tunneling microscopy.
Claim 16
Dependent Claim
14 words
The method as in claim 12 wherein the analysis means is atomic force microscopy.
Claim 17
Dependent Claim
14 words
The method as in claim 12 wherein the analysis means is Auger electron spectroscopy.
Claim 18
Dependent Claim
15 words
The method as in claim 12 wherein the analysis means is angle-dependent x-ray photoelectron spectroscopy.
Claim 19
Dependent Claim
12 words
The method as in claim 12 wherein the nucleic acid is DNA.
Claim 20
Dependent Claim
12 words
The method as in claim 12 wherein the nucleic acid is RNA.
Claim 21
Dependent Claim
70 words
The method as in claim 12 wherein step (b) comprises placing a solution of the thiolated nucleic acid on the surface of the gold substrate and permitting the thiolated nucleic acid solution and gold substrate to incubate together for a sufficient time for a soft acid/soft base reaction to occur between each sulfur atom and the gold such that covalent bonds are formed between each sulfur atom and the gold.
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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) | 1998-12-04 | 1999-06-05 | 1999-12-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-12-04 | 2003-06-05 | 2003-12-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-12-04 | 2007-06-05 | 2007-12-05 | $7700.00 | Window Closed / Lapsed |