Methods and compositions for sequencing double stranded nucleic acids
A method for determining sequences from sense and antisense strands of a nucleic acid, including (a) providing a nucleic acid cluster attached to a solid support, wherein the nucleic acid cluster includes a sense strand and an antisense strand of a concatemer, the concatemer including multiple copies of a sequence unit, the sequence unit including a target sequence and a primer binding site; (b) hybridizing a primer to a primer binding site in the antisense strand; (c) extending the primer along the antisense strand to determine the sequence from at least a portion of the target sequence in the antisense strand; (d) hybridizing a second primer to a primer binding site in the sense strand; and (e) extending the second primer along the sense strand to determine the sequence from at least a portion of the target sequence in the sense strand.
1. A method for determining sequences from sense and antisense strands of a nucleic acid, comprising
(a) providing a nucleic acid cluster attached to a solid support, wherein the nucleic acid cluster comprises a sense strand of a concatemer and an antisense strand of the concatemer, wherein the concatemer comprises multiple copies of a sequence unit linked in series, wherein the sequence unit comprises a target sequence and a primer binding site;
(b) hybridizing a primer to the primer binding site in a sequence unit of the antisense strand in the cluster;
(c) extending the primer along the antisense strand to determine the sequence from at least a portion of the target sequence in the antisense strand;
(d) removing the antisense strand from the cluster prior to steps (e) and (f);
(e) hybridizing a second primer to the primer binding site in a sequence unit of the sense strand; and
(f) extending the second primer along the sense strand to determine the sequence from at least a portion of the target sequence in the sense strand.
2. The method of claim 1 , further comprising, prior to step (e), adding a blocking moiety to the extended primer, thereby preventing further extension of the extended primer during step (f).
3. The method of claim 1 , further comprising, prior to step (e), adding a capping moiety to the extended primer, thereby preventing polymerase from binding the 3′ end of the extended primer during step (f).
4. The method of claim 1 , wherein the extending of the primer in step (c) comprises repeated cycles of (i) adding a reversibly terminated nucleotide to the primer and (ii) deblocking the reversibly terminated nucleotide on the primer.
5. The method of claim 4 , wherein the reversibly terminated nucleotide comprises a label that is detected to produce a signal, the signal being used to determine the sequence from at least the portion of the target sequence in the antisense strand.
6. The method of claim 4 , wherein the repeated cycles further comprise (iii) detecting a stabilized ternary complex comprising a polymerase, next correct nucleotide and the primer hybridized to the antisense strand.
7. The method of claim 1 , wherein step (a) comprises
(i) providing a solid support comprising a capture primer,
(ii) hybridizing a nucleic acid template to the primer,
(iii) synthesizing the sense strand by extending the capture primer along the nucleic acid template by rolling circle amplification, and
(iv) synthesizing the antisense strand by extending an amplification primer that binds to the primer binding site in a sequence unit of the sense strand,
wherein the extending of the capture primer and the extending of the amplification primer are carried out using a strand displacing polymerase.
8. The method of claim 7 , wherein the nucleic acid template is a circular nucleic acid template.
9. The method of claim 7 , further comprises circularizing the nucleic acid template subsequent to step (a) (ii) and prior to step (a) (iii).
10. The method of claim 7 , wherein the amplification primer is not covalently attached to the solid support.
11. The method of claim 7 , further comprising, prior to step (b), adding capping moieties to 3′ ends in the nucleic acid cluster attached to the solid support.
12. The method of claim 1 , wherein the cluster comprises multiple antisense strands of the concatemer.
13. The method of claim 7 , wherein the nucleic acid cluster is attached to the solid support by covalent attachment of the sense strand to the solid support.
14. The method of claim 13 , wherein the antisense strand is attached to the cluster by Watson-Crick base pairing to the sense strand, and wherein the antisense strand does not have a covalent bond to the solid support.
15. The method of claim 1 , wherein the sense strand is synthesized by extending a capture primer of a plurality of capture primers covalently attached to a solid support and hybridized to the primer binding site of a nucleic acid template, and wherein the antisense strand is synthesized by extending an amplification primer of a plurality of amplification primers covalently attached to the solid support and hybridized to the primer binding site in a sequence unit of the sense strand.
16. The method of claim 15 , wherein a density of the plurality of capture primers on the solid support is lower than a density of the plurality of amplification primers on the solid support.
17. The method of claim 1 , wherein the antisense strand is synthesized by extending an amplification primer in the presence of deoxyribonucleotide triphosphates comprising dATP, dTTP, dGTP, dCTP, and a modified or non-canonical deoxyribonucleotide triphosphate, and wherein the non-canonical deoxyribonucleotide trisphosphate is dUTP.
18. The method of claim 17 , further comprising digesting the antisense strand hybridized to the extended primer.
19. The method of claim 18 , wherein said digesting comprises digesting the antisense strand hybridized to the extended primer using Uracil DNA glycosylase (UDG), Endonuclease VIII, and T7 Exonuclease.