Multi-omic analysis in monodisperse droplets
This disclosure provides methods and systems for single-cell, multi-omic analysis of target cells without microfluidic devices. The disclosed methods involve the use of template particles to template the formation of monodisperse droplets to generally capture a single target cell from a population of cells in an encapsulation, derive a plurality of distinct mRNA molecules from the single target cell, and quantify the distinct mRNA molecules to generate an expression profile. Nucleic-acid-tagged antibody conjugates are used for simultaneous proteomic analysis along with the gene expression profiling.
1. A method for single cell analysis, the method comprising:
incubating a plurality of nucleic-acid-labelled, target-specific antibodies with a plurality of target cells to promote binding of the nucleic-acid-labelled, target-specific antibodies to target proteins expressed by the target cells;
washing the incubated target cells to remove unbound nucleic-acid-labelled, target-specific antibodies;
combining template particles and the washed target cells in a first fluid, wherein each template particle comprises first capture probes comprising capture sequences and second capture probes comprising template-switching oligos (TSOs);
adding a second fluid to the first fluid;
shearing the fluids to generate a plurality of monodisperse droplets simultaneously that contain a single one of the template particles and a single one of the target cells;
amplifying and sequencing nucleic acid labels from the nucleic-acid-labelled, target-specific antibodies to identify target proteins expressed by the target cells.
2. The method of claim 1 further comprising quantifying the target proteins expressed by the target cells.
3. The method of claim 2 wherein the nucleic acid labels comprise a unique molecular identifier sequence.
4. The method of claim 2 wherein the nucleic acid labels comprise a PCR handle.
5. The method of claim 1 , wherein the template particles further comprise one or more compartments.
6. The method of claim 5 , wherein the one or more compartments contain a reagent selected from a group comprising a lytic reagent, a nucleic acid synthesis reagent, or combination thereof.
7. The method of claim 6 further comprising, prior to the step of amplifying and sequencing nucleic acid labels, lysing each of the single target cells contained within the monodisperse droplets to release a plurality of distinct mRNA molecules;
capturing the plurality of distinct mRNA molecules with the first capture probes;
extending the first capture probes with reverse transcriptase to form nascent first strand cDNAs;
annealing the nascent first strand cDNAs to the TSOs and copying the TSOs to generate cDNAs that are bound to the template particles and contain copies of the plurality of distinct mRNA molecules and the TSOs;
breaking the droplets to release the cDNA; and
amplifying and sequencing the cDNA to quantify the plurality of distinct mRNA molecules.
8. The method of claim 7 wherein the nucleic acid labels comprise a capture portion.
9. The method of claim 8 wherein the capture portion comprises a poly A sequence.
10. The method of claim 7 , further comprising generating an expression profile for each of the single target cells after quantifying the plurality of distinct mRNA molecules.
11. The method of claim 1 , wherein the first fluid is an aqueous fluid.
12. The method of claim 11 , wherein the second fluid comprises an oil.
13. The method of claim 12 , wherein shearing the fluids comprises one of using a vortexer or pipetting.
14. The method of claim 6 , wherein the nucleic acid synthesis reagent comprises a polymerase.
15. The method of claim 6 , wherein the reagent is released from the one or more compartments in response to an external stimulus.
16. The method of claim 8 , wherein the template particles further comprise a plurality of capture probes comprising:
a universal primer sequence;
at least one barcode; and
a capture sequence that hybridizes to one or more of the plurality of distinct mRNA.
17. The method of claim 16 , wherein the capture sequence is selected from one of a poly T nucleotide sequence, a gene-specific nucleotide sequence, or a random nucleotide sequence.
18. The method of claim 16 , wherein the capture sequence of one or more of the capture probes hybridizes to the capture portion of one or more of the nucleic acid labels.
19. The method of claim 16 , wherein mRNA attached to the template particle by the capture probes is reverse transcribed to generate a first strand comprising cDNA and the barcode sequence.