Spatially encoded biological assays
The present invention provides assays and assay systems for use in spatially encoded biological assays. The invention provides an assay system comprising an assay capable of high levels of multiplexing where reagents are provided to a biological sample in defined spatial patterns; instrumentation capable of controlled delivery of reagents according to the spatial patterns; and a decoding scheme providing a readout that is digital in nature.
1. A method for determining a location of a protein and a nucleic acid in a biological sample, the method comprising:
(a) contacting the biological sample with a binding agent that specifically binds to the protein, wherein the binding agent is coupled to an oligonucleotide comprising a sequence;
(b) contacting the biological sample with an array comprising a first capture probe and a second capture probe, wherein:
the first capture probe comprises (i) a first target-binding domain that hybridizes to the oligonucleotide coupled to the binding agent, and (ii) a nucleic acid sequence that identifies a unique location of the first capture probe on the array; and
the second capture probe comprises (i) a second target-binding domain that hybridizes to the nucleic acid of the biological sample, and (ii) a nucleic acid sequence that identifies the unique location of the second capture probe on the array;
(c) determining (i) a sequence of the oligonucleotide coupled to the binding agent, or a complement thereof, and (ii) the nucleic acid sequence that identifies the unique location of the first capture probe on the array, or a complement thereof, and using the determined sequences of (i) and (ii) to determine the location of the protein in the biological sample; and
(d) determining (i) all or a portion of a sequence of the nucleic acid of the biological sample, or a complement thereof, and (ii) the nucleic acid sequence that identifies the unique location of the second capture probe on the array, or a complement thereof, and using the determined sequences of (i) and (ii) to determine the location of the nucleic acid in the biological sample.
2. The method of claim 1 , wherein the second target-binding domain of the second capture probe, when bound to the nucleic acid of the biological sample, can function as a primer.
3. The method of claim 1 , wherein the determining in step (d) comprises nucleic acid amplification.
4. The method of claim 1 , wherein the determining in step (d) comprises sequencing (i) all or a portion of the sequence of the nucleic acid of the biological sample, or the complement thereof, and (ii) the nucleic acid sequence that identifies the unique location of the second capture probe on the array, or the complement thereof.
5. The method of claim 1 , wherein the second capture probe further comprises one or both of a primer region and an adaptor region.
6. The method of claim 5 , wherein one or both of the primer region and the adaptor region comprise(s) a universal nucleotide sequence.
7. The method of claim 1 , wherein the nucleic acid is DNA.
8. The method of claim 7 , wherein the DNA is genomic DNA.
9. The method of claim 1 , wherein the nucleic acid is RNA.
10. The method of claim 9 , wherein the RNA is mRNA.
11. The method of claim 10 , wherein the determining in step (d) includes generation of a cDNA using the second target-binding domain of the second capture probe, bound to the nucleic acid of the biological sample, as a primer.
12. The method of claim 11 , wherein the cDNA comprises the nucleic acid sequence that identifies the unique location of the second capture probe on the array, and a sequence complementary to all or a portion of the sequence of the nucleic acid of the biological sample.
13. The method of claim 11 , wherein the determining in step (d) further comprises amplifying the cDNA.
14. The method of claim 1 , wherein the nucleic acid comprises a single nucleotide polymorphism (SNP) or a mutation.
15. The method of claim 1 , wherein the binding agent is an antibody or an antibody fragment capable of binding to the protein.
16. The method of claim 1 , wherein the determining in step (c) comprises nucleic acid amplification.
17. The method of claim 1 , wherein the determining in step (c) comprises sequencing (i) the oligonucleotide coupled to the binding agent, or the complement thereof, and (ii) the nucleic acid sequence that identifies the unique location of the first capture probe on the array, or a complement thereof.
18. The method of claim 1 , wherein the first capture probe further comprises one or both of a primer region and an adaptor region.
19. The method of claim 18 , wherein one or both of the primer region and the adaptor region comprise(s) a universal nucleotide sequence.
20. The method of claim 1 , wherein the first target-binding domain of the first capture probe comprises a sequence that is complementary to the oligonucleotide coupled to the binding agent.
21. The method of claim 1 , wherein the biological sample comprises diseased tissue.
22. The method of claim 21 , wherein the diseased tissue comprises cancerous tissue, or an infected or inflamed tissue.
23. The method of claim 1 , wherein the array comprises a bead array.
24. The method of claim 1 , wherein the biological sample is a tissue section.
25. The method of claim 24 , wherein the tissue section is a fresh frozen tissue section.
26. The method of claim 24 , wherein the tissue section is a formalin-fixed paraffin-embedded (FFPE) tissue section.
27. The method of claim 24 , wherein the tissue section comprises tissue from a subject, and the method further comprises performing steps (a) through (d) on additional, serial tissue section(s) obtained from the subject.
28. The method of claim 1 , wherein the method further comprises obtaining an image of the biological sample contacted with the array.
29. The method of claim 28 , wherein the image is obtained using, at least in part, immunohistochemistry or staining.
30. The method of claim 1 , wherein the method further comprises generating a map of the location(s) of the protein and/or the nucleic acid in the biological sample.