Single cell analysis of transposase accessible chromatin
Methods and systems for sample preparation techniques that allow amplification (e.g., whole genome amplification) and sequencing of chromatin accessible regions of single cells are provided. The methods and systems generally operate by forming or providing partitions (e.g., droplets) including a single biological particle and a single bead comprising a barcoded oligonucleotide. The preparation of barcoded next-generation sequencing libraries prepared from a single cell is facilitated by the transposon-mediated transposition and fragmentation of a target nucleic acid sequence. The methods and systems may be configured to allow the implementation of single-operation or multi-operation chemical and/or biochemical processing within the partitions.
1. A method of generating a barcoded nucleic acid fragment, comprising:
(a) providing a plurality of cells or cell nuclei comprising a plurality of template nucleic acid molecules;
(b) from said plurality of cells or cell nuclei, generating a plurality of biological particles comprising a plurality of template nucleic acid fragments of said plurality of template nucleic acid molecules using a plurality of transposase-nucleic acid complexes, each comprising a transposase molecule and a transposon end oligonucleotide molecule;
(c) generating a plurality of partitions, wherein a partition of said plurality of partitions comprises (i) a single biological particle of said plurality of biological particles, said single biological particle comprising a template nucleic acid fragment of said plurality of template nucleic acid fragments, and (ii) a single bead having attached thereto a plurality of barcode oligonucleotide molecules each comprising a barcode sequence; and
(d) in said partition, generating a barcoded nucleic acid fragment using at least (i) said template nucleic acid fragment, and (ii) a barcode oligonucleotide molecule of said plurality of barcode oligonucleotide molecules.
2. The method of claim 1 , wherein said single bead is a gel bead.
3. The method of claim 1 , wherein said plurality of barcode oligonucleotide molecules is releasably attached to said single bead.
4. The method of claim 3 , further comprising releasing said plurality of barcode oligonucleotide molecules from said single bead.
5. The method of claim 2 , wherein said partition further comprises a reducing agent to depolymerize said gel bead.
6. The method of claim 5 , wherein said reducing agent is dithiothreitol (DTT).
7. The method of claim 1 , wherein said plurality of partitions is a plurality of droplets.
8. The method of claim 1 , wherein said plurality of partitions is a plurality of wells.
9. The method of claim 1 , further comprising amplifying said barcoded nucleic acid fragment, or a derivative thereof, by nucleic acid amplification.
10. The method of claim 1 , wherein said barcoded nucleic acid fragment is released from said partition.
11. The method of claim 1 , further comprising sequencing said barcoded nucleic acid fragment, or a derivative thereof.
12. The method of claim 1 , wherein each of said plurality of transposase-nucleic acid complexes comprise (i) a first oligonucleotide molecule comprising a transposon end sequence and a first primer sequence; and (ii) a second oligonucleotide molecule comprising a transposon end sequence and a second primer sequence.
13. The method of claim 12 , wherein (i) said first oligonucleotide molecule is a partially double-stranded molecule and comprises a first strand comprising said first primer sequence and said transposon end sequence and a second strand comprising a sequence at least 80% complementary to said transposon end sequence; and (ii) said second oligonucleotide molecule is a partially double-stranded molecule and comprises a first strand comprising said second primer sequence and said transposon end sequence and a second strand comprising a sequence at least 80% complementary to said transposon end sequence.
14. The method of claim 12 , wherein each of said plurality of barcode oligonucleotide molecules comprise an adapter sequence, a barcode sequence, and a sequence at least 80% complementary to said first primer sequence.
15. The method of claim 13 , wherein each of said plurality of barcode oligonucleotides are partially double-stranded molecules comprising a first strand comprising an adapter sequence, a barcode sequence, and a sequence at least 80% complementary to said first primer sequence and a second strand comprising a sequence at least 80% complementary to said adapter sequence and a sequence at least 80% complementary to said barcode sequence.
16. The method of claim 15 , wherein said barcoded nucleic acid fragment is generated by ligation of said barcode oligonucleotide molecule with said template nucleic acid fragment.
17. The method of claim 16 , wherein subsequent to said ligation, said template nucleic acid fragment is subjected to a gap-filling reaction to generate a gap-filled, template nucleic acid fragment.
18. The method of claim 14 , wherein said template nucleic acid fragment is subjected to a gap-filling reaction to generate a gap-filled, template nucleic acid fragment and wherein said barcoded nucleic acid fragment is generated by amplification of said template nucleic acid fragment, or a derivative thereof, with said barcode oligonucleotide molecule.
19. The method of claim 18 , wherein each of said plurality of barcode oligonucleotide molecules are single-stranded.
20. The method of claim 1 , further comprising sequencing said barcoded template nucleic acid fragment, or a derivative thereof.
21. The method of claim 1 , wherein said plurality of cells or cell nuclei comprises chromatin comprising said plurality of template nucleic acid molecules.
22. The method of claim 21 , wherein said barcoded nucleic acid fragment, or a derivative thereof, is indicative of a region of accessible chromatin.
23. The method of claim 12 , wherein said first primer sequence and said second primer sequence are the same.
24. The method of claim 12 , wherein said first primer sequence and said second primer sequence are the different.
25. The method of claim 1 , wherein, in (c), said single biological particle is a single nucleus comprising said template nucleic acid fragment.
26. The method of claim 1 , wherein said single biological particle is a cell bead comprising said template nucleic acid fragment.
27. The method of claim 2 , wherein each of the plurality of barcode oligonucleotide molecules are releasably attached to said single gel bead through a labile bond.
28. The method of claim 27 , wherein the labile bond is selected from the group consisting of a thermally cleavable bond, a chemically labile bond, and a photo-sensitive bond.
29. The method of claim 27 , wherein the labile bond comprises a linkage selected from the group consisting of an ester linkage, a vicinal diol linkage, a Diels-Alder linkage, a sulfone linkage, a silyl ester linkage, a glycosidic linkage, a peptide linkage, or a phosphodiester linkage.