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 of determining presence of a target biological molecule at multiple regions of interest in a tissue sample, comprising:
(a) delivering a plurality of probes to a tissue sample, wherein at least a subset of probes of the plurality of probes comprise a capture agent that specifically binds to a target biological molecule of the tissue sample, wherein the capture agent is conjugated to an oligonucleotide;
(b) separating the probes of the subset of probes comprising the capture agent specifically bound to the target biological molecule at the multiple regions of interest in the tissue sample from probes of the subset of probes not specifically bound to the target biological molecule at the multiple regions of interest in the tissue sample;
(c) removing the oligonucleotides from the probes comprising the capture agent specifically bound to the target biological molecule from the multiple regions of interest and determining a sequence of the oligonucleotides via hybridization of one or more labelled probe(s) comprising a label; and
(d) using the determined sequence of the oligonucleotides to determine presence of the target biological molecule at the multiple regions of interest in the tissue sample.
2. The method of claim 1 , wherein the method further comprises obtaining an image of the tissue sample.
3. The method of claim 1 , wherein step (b) comprises washing the tissue sample to separate the probes of the subset of probes comprising the capture agent specifically bound to the target biological molecule at the multiple regions of interest in the tissue sample from the probes of the subset of probes not specifically bound to the target biological molecule at the multiple regions of interest in the tissue sample.
4. The method of claim 1 , wherein step (c) comprises detecting the label of the one or more labelled probe(s).
5. The method of claim 1 , wherein the label of the one or more labelled probe(s) is a fluorophore.
6. The method of claim 5 , wherein step (c) comprises detecting the fluorophore.
7. The method of claim 1 , wherein the target biological molecule comprises a nucleic acid.
8. The method of claim 7 , wherein the nucleic acid is mRNA.
9. The method of claim 7 , wherein the nucleic acid is genomic DNA.
10. The method of claim 1 , wherein the target biological molecule comprises a protein.
11. The method of claim 10 , wherein the protein is an enzyme.
12. The method of claim 11 , wherein the enzyme comprises a kinase, a phosphatase, a zymogen, a protease, or a fragment thereof.
13. The method of claim 1 , wherein the capture agent is a small molecule, an aptamer, or a substrate for an enzyme.
14. The method of claim 1 , wherein the capture agent is an antibody.
15. The method of claim 1 , wherein two or more probes of the subset of probes specifically bind to unique target biological molecules of the tissue sample.
16. The method of claim 15 , wherein step (c) comprises determining all or a portion of the sequence of the oligonucleotides of the two or more probes of the subset of probes in parallel.
17. The method of claim 15 , wherein the two or more probes is at least one thousand probes.
18. The method of claim 1 , wherein the method further comprises detecting differential expression of the target biological molecule in the multiple regions of interest of the tissue sample.
19. The method of claim 18 , wherein the differential expression of the target biological molecule is associated with a biological structure or cell type.
20. The method of claim 18 , wherein the differential expression of the target biological molecule comprises gene expression.
21. The method of claim 18 , wherein the differential expression of the target biological molecule comprises protein expression.
22. The method of claim 1 , wherein the multiple regions of interest are determined by histological features of the tissue sample.
23. The method of claim 1 , wherein the tissue sample is a tissue section.
24. The method of claim 23 , wherein the tissue section comprises a fresh-frozen tissue section.
25. The method of claim 23 , wherein the tissue section comprises a formalin-fixed paraffin embedded tissue section.
26. The method of claim 1 , wherein the capture agent comprises a nucleic acid and the target biological molecule comprises an RNA.
27. The method of claim 1 , wherein the capture agent comprises a nucleic acid and the target biological molecule comprises a DNA.
28. The method of claim 1 , wherein the capture agent comprises an antibody and the target biological molecule comprises a protein.
29. The method of claim 1 , wherein the method further comprises obtaining an image of the tissue sample to identify the multiple regions of interest in the tissue sample.
30. The method of claim 1 , wherein the subset of probes of the plurality of probes comprise a capture agent that specifically binds to different target biological molecules of the tissue sample.