Spatially encoded biological assays
Provided herein are methods of identifying a target protein in a tissue sample that include delivering a plurality of probes to a tissue sample, where a probe of the plurality of probes comprises an antibody conjugated to an oligonucleotide having a sequence, where the antibody specifically binds to the target protein in the tissue sample; amplifying the oligonucleotide to generate an amplicon comprising copies of the oligonucleotide; detecting all or a portion of a copy of the oligonucleotide in the amplicon; and using the detected sequence to identify the target protein in the tissue sample.
1. A method of identifying a target protein in a tissue sample comprising:
(a) delivering a plurality of probes to a tissue sample, wherein a probe of the plurality of probes comprises an antibody conjugated to an oligonucleotide having a sequence, and wherein the antibody specifically binds the target protein in the tissue sample;
(b) amplifying the oligonucleotide to generate an amplicon comprising copies of the oligonucleotide;
(c) detecting all or a portion of a copy of the oligonucleotide in the amplicon by:
(i) hybridizing a probe comprising a sequence that is 100% complementary to a portion of the sequence of the oligonucleotide and a label, to a copy of the oligonucleotide in the amplicon; and
(ii) imaging the tissue sample after (i) to detect the label in the tissue sample; and
(d) using the detected sequence to identify the target protein in the tissue sample.
2. The method of claim 1 , wherein the method further comprises separating one or more probes of the plurality of probes that are not bound to the target protein from the tissue sample.
3. The method of claim 2 , wherein the separating comprises washing the tissue sample to separate the probes that are not bound to the target protein from the tissue sample.
4. The method of claim 1 , wherein the label comprises a fluorophore.
5. The method of claim 1 , wherein the method further comprises identifying a region of interest in the tissue sample.
6. The method of claim 1 , wherein the method further comprises associating the image of the tissue sample with the detected sequence, thereby identifying one or more target protein locations in the tissue sample.
7. The method of claim 1 , wherein the method further comprises associating a location of the label in the image of the tissue sample with the detected sequence, thereby identifying a location of the target protein in the tissue sample.
8. The method of claim 1 , wherein the tissue sample comprises a tissue section.
9. The method of claim 1 , wherein the tissue sample comprises a formalin-fixed paraffin embedded tissue sample.
10. The method of claim 1 , wherein the tissue sample comprises fresh-frozen tissue sample.
11. The method of claim 1 , wherein the method further comprises determining an abundance of the target protein in the tissue sample.
12. The method of claim 11 , wherein the plurality of probes comprises multiple probes that bind to the target protein in the tissue sample, and wherein determining the abundance of the target protein comprises:
hybridizing probes each comprising a sequence that is 100% complementary to a portion of the sequence of the oligonucleotide, and the label, to copies of the oligonucleotide in the amplicon;
imaging the tissue sample after hybridizing the probes to detect the labels of the hybridized probes, and
quantifying an amount of the hybridized probes in the tissue sample based on the detected labels to determine the abundance of the target protein.
13. The method of claim 1 , wherein four or more probes of the plurality of probes specifically bind to different target proteins in the tissue sample.