Oligonucleotide encoded chemical libraries
This application provides a bead with a covalently attached chemical compound and a covalently attached DNA barcode and methods for using such beads. The bead has many substantially identical copies of the chemical compound and many substantially identical copies of the DNA barcode. The compound consists of one or more chemical monomers, where the DNA barcode takes the form of barcode modules, where each module corresponds to and allows identification of a corresponding chemical monomer. The nucleic acid barcode can have a concatenated structure or an orthogonal structure. Provided are method for sequencing the bead-bound nucleic acid barcode, for cleaving the compound from the bead, and for assessing biological activity of the released compound.
1. A method for identifying a cellular transcriptome change induced by a compound, wherein said compound is included in an assay of a combinatorial chemical library, the method comprising:
a) generating an assay array wherein said array comprises:
i) a plurality of confined volumes wherein each confined volume is separated from the other confined volumes and wherein each confined volume comprises a cell;
ii) a plurality of beads where each bead comprises a plurality of substantially the same compound from said combinatorial library and a plurality of functionalized oligonucleotides, wherein said functionalized oligonucleotide comprises a RNA capturing element and an oligonucleotide portion that encodes the structure of the compound or the synthetic steps used to make said compound, wherein a single bead is disposed in each confined volume;
b) contacting the cell in each confined volume with the compound released into the confined volume from the bead and maintaining said contact for a period sufficient to generate a transcriptome change in the RNA expressed by the cell in response to said contacting; and
c) capturing the RNA from the cell by lysing the cell and contacting the RNA with the RNA capturing element on said bead.
2. The method of claim 1 , further comprising removing the bead from the confined volume.
3. The method of claim 1 , wherein the RNA capturing element is a nucleic acid.
4. The method of claim 3 , wherein the nucleic acid is DNA or RNA.
5. The method of claim 4 , wherein the nucleic acid is complementary to at least a portion of the RNA.
6. The method of claim 5 , wherein the RNA capturing element comprises poly-deoxythymidine (poly(dT)), an exon-targeting RNA probe, or microRNA (miRNA).
7. The method of claim 1 , wherein the RNA capturing element is an absorbent material capable of binding mRNA.
8. The method of claim 1 , wherein the plurality of substantially the same compound is attached to the bead via cleavable linker.
9. The method of claim 8 , wherein contacting the cell in each confined volume with the compound from the bead in the confined volume comprises cleaving the linker to remove at least a portion of the compound from the bead.
10. The method of claim 9 , wherein said cleavable linker is cleaved by light, temperature change, pH change, sound, salt, or a change in oxidation.
11. The method of claim 10 , wherein the cleavable linker is cleaved by light.
12. The method of claim 11 , wherein the light is UV light.
13. The method of claim 1 , wherein the plurality of functionalized oligonucleotides are attached to the bead via a non-cleavable bond.
14. The method of claim 1 , wherein the confined volumes are droplets.
15. The method of claim 1 , wherein the confined volumes are picowells.
16. The method of claim 1 , wherein each confined volume comprises multiple cells.
17. The method of claim 1 , wherein the cell is lysed by addition of a detergent, repeated addition of freeze/thaw cycles, heating, addition of membrane disrupting peptides, mechanical agitation, or any combination thereof.
18. The method of claim 1 , wherein the functionalized oligonucleotide is sequenced.
19. The method of claim 1 , wherein the RNA is messenger RNA (mRNA).
20. The method of claim 19 , wherein the transcriptome change comprises one or more changes in the mRNA in the cell.
21. The method of claim 1 , wherein the RNA is microRNA (miRNA).
22. The method of claim 21 , wherein the transcriptome change comprises one or more changes in the miRNA level in the cell.
23. The method of claim 1 , wherein the functionalized oligonucleotide comprises DNA.
24. The method of claim 1 , wherein the plurality of substantially the same compound was attached to the bead surface by joining multiple compound building blocks, wherein all of the building blocks when joined comprise the compound.
25. The method of claim 24 , wherein the functionalized oligonucleotide encodes the synthetic steps used to prepare the compound.
26. The method of claim 1 , wherein the cell is selected from:
(i) a mammalian cell that is not a cancer cell;
(ii) a mammalian cancer cell;
(iii) a dead mammalian cell;
(iv) an apoptotic mammalian cell;
(v) a necrotic mammalian cell;
(vi) a bacterial cell;
(vii) a plasmodium cell;
(viii) a cell that is metabolically active but has a cross-linked genome and is unable to undergo cell division; and
(ix) a mammalian cell that is infected with a virus.
27. The method of claim 1 , wherein the cell is a human cell.
28. The method of claim 27 , wherein the human cell is a cancer cell.
29. The method of claim 28 , wherein the human cell is a primary cell.
30. The method of claim 29 , wherein the human cell is obtained from a biopsy of normal tissue, a biopsy from a solid tumor, or from a hematological cancer, or from circulating solid tumor cells.