Methods and compositions for tagging and analyzing samples
The invention relates to methods of tagging analytes in a sample.
1. A method of tagging target oligonucleotides comprising:
a. partitioning DNA into a plurality of compartments, wherein the DNA comprises an RNA polymerase promoter sequence, a tag sequence and a hybridization region capable of hybridizing to one or more target oligonucleotides, and wherein the plurality of compartments or a subset thereof further comprises an RNA polymerase and ribonucleotide triphosphates;
b. performing an in vitro transcription reaction on the DNA within the compartments, thereby obtaining compartments comprising RNA, wherein the RNA comprises the tag sequence and the hybridization region;
c. merging the interior of the compartments comprising RNA with the interior of a set of compartments comprising target oligonucleotides, wherein prior to the merging, the compartments comprising target oligonucleotides are physically separate from the compartments comprising RNA;
d. hybridizing the RNA to the target oligonucleotides, wherein the hybridization region of the RNA hybridizes to a region of the target oligonucleotides; and
e. performing a reaction to attach a sequence corresponding to the RNA to the target oligonucleotides, thereby tagging the target oligonucleotides.
2. The method of claim 1 , wherein the DNA is double stranded.
3. The method of claim 1 , wherein the compartments are droplets within an oil-and-water emulsion.
4. The method of claim 1 , wherein the tag sequence comprises a cell tag, a molecule tag or a combination thereof.
5. The method of claim 1 , wherein the target oligonucleotides are DNA.
6. The method of claim 1 , wherein partitioning the target oligonucleotides comprises partitioning one or more cells within individual compartments of the set, and lysing the one or more cells to liberate cellular oligonucleotides, wherein the cellular oligonucleotides are the target oligonucleotides.
7. The method of claim 1 , wherein the target oligonucleotides are cellular oligonucleotides.
8. The method of claim 7 , wherein the cellular oligonucleotides are cellular mRNA.
9. The method of claim 8 , further comprising conducting a reverse transcription on the cellular mRNA to generate cellular cDNA.
10. The method of claim 9 , wherein the target oligonucleotides are the cellular cDNA.
11. The method of claim 1 , wherein the reaction is a Rapid Amplification of cDNA Ends (RACE) reaction.
12. The method of claim 9 , wherein the reverse transcription reaction is performed with a primer specific for a region of the genome.
13. The method of claim 1 , wherein the DNA is conjugated to a solid support.
14. The method of claim 13 , wherein the solid support is a bead.
15. The method of claim 9 , wherein the reverse transcription reaction is conducted within the set of compartments prior to the merging step.
16. The method of claim 9 , wherein the reverse transcription reaction is conducted within the merged compartments.
17. The method of claim 12 , wherein the region of the genome is an immunoglobulin gene or a T-cell receptor gene.
18. The method of claim 1 , wherein the target oligonucleotides are cDNA generated from cellular mRNA.
19. The method of claim 1 , wherein the hybridization region of the RNA comprises a homopolymeric tail.
20. The method of claim 18 , wherein cDNA comprises overhanging C bases generated via the terminal transferase activity of a reverse transcriptase enzyme.
21. The method of claim 20 , wherein the hybridization region of the RNA comprises a homopolymeric tail.
22. The method of claim 21 , wherein the homopolymeric tail comprises a series of G bases.
23. The method of claim 22 , wherein the hybridizing comprises hybridizing the series of G bases to the overhanging C bases.
24. The method of claim 1 , wherein the RNA polymerase promoter sequence is the T7 RNA polymerase promoter sequence.
25. The method of claim 1 , wherein the RNA polymerase promoter sequence is the T3 RNA polymerase promoter sequence.