Methods of detecting analytes
Localized detection of RNA in a tissue sample that includes cells is accomplished on an array. The array include a number of features on a substrate. Each feature includes a different capture probe immobilized such that the capture probe has a free 3′ end. Each feature occupies a distinct position on the array and has an area of less than about 1 mm 2 . Each capture probe is a nucleic acid molecule, which includes a positional domain including a nucleotide sequence unique to a particular feature, and a capture domain including a nucleotide sequence complementary to the RNA to be detected. The capture domain can be at a position 3′ of the positional domain.
1. A method for determining the location of a nucleic acid in a tissue section comprising:
a) providing a substrate comprising a plurality of capture probes, wherein a capture probe of the plurality of capture probes comprises:
(i) a capture domain that binds the nucleic acid, and
(ii) a positional domain comprising a nucleotide sequence, wherein the nucleotide sequence of each of the positional domains is unique to a distinct position in the substrate;
b) contacting the tissue section with the substrate;
c) releasing the capture probe from the substrate;
d) extending a 3′ end of the capture probe using the nucleic acid of the tissue section bound to the capture domain as a template to generate an extended nucleic acid product; and
e) determining (i) all or a part of the nucleotide sequence of the nucleic acid of the tissue section bound to the capture domain, or a complement thereof, and (ii) the nucleotide sequence of the positional domain, or a complement thereof, wherein the nucleotide sequences of (i) and (ii) indicate the nucleic acid was obtained from the tissue section at a distinct position on the substrate by the capture probe, thereby determining the location of the nucleic acid in the tissue section.
2. The method of claim 1 , wherein the substrate comprises a polymer.
3. The method of claim 1 , wherein the nucleic acid is DNA.
4. The method of claim 1 , wherein the nucleic acid is RNA.
5. The method of claim 1 , wherein the capture domain comprises a nucleotide sequence for the capture of mRNA, wherein in the capture domain comprises a poly-T sequence.
6. The method of claim 2 , wherein the polymer is affixed to a solid support.
7. The method of claim 6 , wherein the solid support comprises one of glass, silicon, poly-lysine coated material, nitrocellulose, polystyrene, cyclic olefin copolymers (COCs), cyclic olefin polymers (COPs), polypropylene, polyethylene, and polycarbonate.
8. The method of claim 1 , wherein the extending in step (d) comprises performing a reverse transcription reaction and wherein the generated extended nucleic acid product is a cDNA.
9. The method of claim 1 , wherein the determining in step (e) comprises amplifying all or a portion of the extended nucleic acid product, or the complement thereof, to generate one or more amplified nucleic acid products.
10. The method of claim 9 , wherein the method further comprises releasing the one or more amplified nucleic acid products from the substrate.
11. The method of claim 1 , wherein the determining in step (e) comprises sequencing.
12. The method of claim 1 , wherein the method further comprises imaging the tissue section, and the method further comprises correlating the nucleotide sequence of the positional domain to the location in the imaged tissue section.
13. The method of claim 12 , wherein the imaging comprises one or more of: light field, bright field, dark field, phase contrast, fluorescence microscopy, reflection, interference, and confocal microscopy.
14. The method of claim 1 , wherein the capture probe comprises the following domains oriented 5′ to 3′:
(i) a cleavage domain,
(ii) the positional domain, and
(iii) the capture domain;
wherein the step of releasing the capture probe from the substrate comprises cleaving the cleavage domain.
15. The method of claim 1 , wherein the releasing in step (c) comprises enzymatic cleavage, chemical cleavage, or applying heat.
16. A method for determining the location of a nucleic acid in a tissue section comprising:
a) providing a substrate comprising a plurality capture probes, wherein a capture probe of the plurality of capture probe comprises:
(i) a capture domain that binds a nucleic acid, and
(ii) a positional domain comprising a nucleotide sequence, wherein the nucleotide sequence of each of the positional domains is unique to a distinct position in the substrate;
b) contacting a tissue section with the substrate;
c) imaging one or more fluorescent marker probes;
d) releasing the capture probe from the substrate;
e) extending a 3′ end of the capture probe using the nucleic acid of the tissue section bound to the capture domain as a template to generate an extended nucleic acid product; and
f) determining (i) all or a part of the nucleotide sequence of the nucleic acid of the tissue section bound to the capture domain, or a complement thereof, and (ii) the nucleotide sequence of the positional domain, or a complement thereof, wherein the nucleotide sequences of (i) and (ii) indicate the nucleic acid was obtained from the tissue section at a distinct position on the substrate by the capture probe, thereby determining the location of the nucleic acid in the tissue section.
17. The method of claim 16 , wherein the substrate comprises a polymer and the polymer is affixed to a solid support.
18. The method of claim 17 , wherein the solid support comprises one of glass, silicon, poly-lysine coated material, nitrocellulose, polystyrene, cyclic olefin copolymers (COCs), cyclic olefin polymers (COPs), polypropylene, polyethylene, and polycarbonate.
19. The method of claim 16 , wherein the nucleic acid is DNA.
20. The method of claim 16 , wherein the nucleic acid is RNA.
21. The method of claim 16 , wherein the capture domain comprises a nucleotide sequence for the capture of mRNA.
22. The method of claim 21 , wherein the capture domain comprises a poly-T sequence.
23. The method of claim 16 , wherein the extending in step (e) comprises performing a reverse transcription reaction and wherein the generated extended nucleic acid product is a cDNA.
24. The method of claim 16 , wherein the determining in (e) comprises amplifying all or a portion of the extended nucleic acid product, or the complement thereof, to generate one or more amplified nucleic acid products.
25. The method of claim 16 , wherein the method further comprises releasing the one or more amplified nucleic acid products from the substrate.
26. The method of claim 16 , wherein the further comprises correlating the nucleotide sequence of the positional domain to the location in the imaged tissue section.
27. The method of claim 16 , wherein the capture probe comprises the following domains oriented 5′ to 3′:
(i) a cleavage domain
(ii) the positional domain, and
(iii) the capture domain;
wherein the step of releasing the capture probe from the substrate comprises cleaving the cleavage domain.
28. The method of claim 16 , wherein the releasing in step (c) comprises enzymatic cleavage, chemical cleavage, or applying heat.
29. The method of claim 16 , wherein the determining in step (e) comprises sequencing.
30. The method of claim 16 , wherein the imaging comprise one or more of: light field, bright field, dark field, phase contrast, fluorescence microscopy, reflection, interference, and confocal microscopy.