Linked ligation
The invention generally relates to capturing, amplifying, and sequencing nucleic acids. In certain embodiments, copies of the sense and antisense strands of a duplex template nucleic acid are captured using linked capture probes and multiple binding and extension steps to improve specificity over traditional single binding target capture techniques. Methods of seeding sequencing clusters with sense and antisense strands of a target nucleic acid are also disclosed including identifying the strands using sense-specific barcodes and confirming base calls using two sense-specific sequencing reads. Linked adapters may be used to increase adapter ligation selectively or efficiency and yield.
1. A method of selectively ligating adapters to a target nucleic acid, the method comprising:
providing a first linked ligation adapter comprising a probe complimentary to a first portion of a target nucleic acid, the probe linked to a first adapter comprising a first universal priming site;
exposing a sample comprising the target nucleic acid to the first linked ligation adapter;
ligating the target nucleic acid to the first linked adapter; and
amplifying the ligated target nucleic acid by PCR using a first universal primer complimentary to the first universal priming site.
2. The method of claim 1 , further comprising sequencing the target nucleic acid wherein the adapter further comprises a sequencing adapter.
3. The method of claim 1 further comprising:
providing a second linked ligation adapter comprising a probe complimentary to a second portion of the target nucleic acid, the probe linked to a second adapter comprising a second universal priming site; and
exposing the sample to the second linked ligation adapter;
ligating the target nucleic acid to the second linked adapter
wherein the ligated target nucleic acid is amplified using the first universal primer and a second universal primer complimentary to the second universal priming site.
4. The method of claim 3 , wherein the sample is simultaneously exposed to the first and second linked ligation adapters.
5. The method of claim 3 , wherein the first and the second portion of the target nucleic acid are the same.
6. The method of claim 5 , wherein the sample is exposed to the second linked ligation adapter after being exposed to the first linked ligation adapter.
7. The method of claim 1 , wherein the target nucleic acid is a fusion nucleic acid.
8. The method of claim 7 , wherein only a portion of the fusion nucleic acid is known.
9. The method of claim 1 , wherein the probe complimentary to the first portion of the target nucleic acid is bound to a solid support proximate to the first adapter wherein the first adapter is also bound to the solid support.
10. The method of claim 9 , further comprising:
providing a second linked ligation adapter comprising a probe complimentary to a second portion of the target nucleic acid, the probe linked to a second adapter comprising a second universal priming site; and
exposing the sample to the second linked ligation adapter;
ligating the target nucleic acid to the second linked adapter;
wherein the sample is amplified using the first universal primer and a second universal primer complimentary to the second universal priming site.
11. The method of claim 10 , further comprising washing the solid support to remove unbound nucleic acids present in the sample before amplification.
12. The method of claim 9 , wherein the solid support is a flow cell.
13. The method of claim 1 , wherein the probe complimentary to the first portion of the target nucleic acid is linked to the first adapter by a linker selected from the group consisting of a polyethylene glycol derivative, an oligosaccharide, a lipid, a hydrocarbon, a polymer, an inverted base, and a protein.
14. The method of claim 13 , wherein the linker is cleavable.
15. The method of claim 1 , wherein the target nucleic acid is double stranded DNA (dsDNA),
wherein the first linked ligation adapter further comprises recombinase complexed with the probe and the first adapter is a double stranded adapter, and
wherein the sample comprising the target nucleic acid is exposed to the first linked ligation adapter in the presence of single stranded binding protein.
16. The method of claim 1 , wherein the adapter comprises a sequence of random nucleotides.
17. The method of claim 1 , wherein the adapter does not comprise a universal priming site.
18. The method of claim 1 , wherein the target nucleic acid is DNA or RNA.
19. The method of claim 1 , wherein the exposing, ligating, and amplifying steps are performed in a droplet.