Compositions and methods for nucleic acid sequencing

Abstract

Embodiments of the present disclosure relate to kits, compositions and methods for nucleic acid sequencing, for example, dual channel nucleic acid synthesis sequencing using blue light excitation and green light excitation. In particular, unlabeled nucleotides for incorporation may be used in combination with an affinity reagent containing a detectable label capable of being excited by blue and / or green light for specific binding to each type of nucleotides incorporated.

Description

Technical Field

[0001] The present disclosure generally relates to compositions, kits, methods, and systems for nucleic acid sequencing applications. Background Art

[0002] Nucleic acid sequencing methods have evolved significantly from the chemical degradation methods used by Maxam and Gilbert and the chain extension methods used by Sanger. Several sequencing methods are used today that allow thousands of nucleic acids to be processed in parallel in a single sequencing run. Instruments that perform such methods are typically large and expensive, as current methods typically rely on large amounts of expensive reagents and multiple sets of optical filters to record the incorporation of nucleic acids into the sequencing reaction.

[0003] It is already clear that the need for high-throughput, smaller, and cheaper DNA sequencing technologies will favor reaping the rewards of genome sequencing. Personalized healthcare is increasingly at the forefront and will benefit from such technologies. Sequencing an individual’s genome to identify potential mutations and abnormalities will be critical to distinguish whether a person has a specific disease and subsequently tailor subsequent therapy to that individual. To accommodate such efforts, sequencing technology should not only have high-throughput capabilities but also be scalable. Therefore, new sequencing methods with improvements in speed, error reading, and cost-effectiveness are now needed. Summary of the invention

[0004] The present disclosure provides next generation sequencing kits, methods, systems and compositions. Certain disclosures relate to kits and compositions for two-channel nucleic acid sequencing applications using blue light excitation and green light excitation (e.g., lasers at 450-460 nm and 520-540 nm).

[0005] One aspect of the present disclosure relates to a kit for sequencing applications, the kit comprising:

[0006] a first type of unlabeled nucleotides comprising a first hapten;

[0007] a second type of unlabeled nucleotides comprising a second hapten;

[0008] a third type of unlabeled nucleotides; and

[0009] A set of affinity reagents, the set of affinity reagents comprising:

[0010] a first affinity reagent comprising a first hapten-binding partner capable of specifically binding to the first type of unlabeled nucleotides; and

[0011] a second affinity reagent comprising a second hapten binding partner capable of specifically binding to the second type of unlabeled nucleotides;

[0012] wherein the first affinity reagent comprises one or more first detectable labels, the one or more first detectable labels are capable of being excited by a first excitation light source, the second affinity reagent comprises one or more second detectable labels, the one or more second detectable labels are capable of being excited by a second excitation light source, and wherein the first detectable label is spectrally distinguishable from the second detectable label; and

[0013] wherein one of the first excitation light source and the second excitation light source has a wavelength of about 450 nm to about 460 nm, and the other of the first excitation light source and the second excitation light source has a wavelength of about 520 nm to about 540 nm;

[0014] One aspect of the present disclosure relates to a protein assembly system comprising:

[0015] a first protein labeled with one or more first detectable labels;

[0016] one or more hapten-containing linkers, the one or more hapten-containing linkers being covalently attached to the first protein; and

[0017] one or more hapten-binding second proteins, the one or more hapten-binding second proteins being conjugated to one or more hapten-containing linkers;

[0018] wherein the one or more hapten-bound second proteins are labeled with one or more second detectable labels, and wherein the one or more first detectable labels are spectrally distinguishable from the one or more second detectable labels.

[0019] Another aspect of the present disclosure relates to a nucleotide complex comprising the protein assembly system described herein. In another aspect, the present disclosure relates to an oligonucleotide or polynucleotide comprising the nucleotide complex described herein.

[0020] A further aspect of the present disclosure relates to the nanoparticle of labeling, and the nanoparticle of this labeling comprises: polymer matrix, and this polymer matrix comprises multiple detectable labels, and wherein the backbone of polymer comprises one or more cleavable parts, and wherein the nanoparticle of this labeling can be degraded into smaller polymeric chains after the cleavage of this cleavable part. In some embodiments, the nanoparticle of this labeling as described herein can be used as a detectable label for this kit as described herein or this protein assembly system. For example, the additional embodiment of the present disclosure includes the nanoparticle of labeling, and the nanoparticle of this labeling also comprises one or more proteins (for example, antibodies) connected thereto or coated thereon.

[0021] A further aspect of the present disclosure relates to the use of the kit in nucleic acid sequencing. For example, the kit can be used in a method for determining the sequence of a plurality of different target polynucleotides, the method comprising:

[0022] (a) contacting a solid support with a solution containing a sequencing primer under hybridization conditions, wherein the solid support comprises a plurality of different target polynucleotides immobilized thereon; and the sequencing primer is complementary to at least a portion of the target polynucleotide;

[0023] (b) contacting the solid support with an aqueous solution comprising a DNA polymerase and one or more of four different types of unlabeled nucleotides under conditions suitable for DNA polymerase-mediated primer extension, and incorporating one type of nucleotide into the sequencing primer to produce an extended copy polynucleotide; wherein

[0024] Each of the four types of nucleotides comprises a 3' blocking group;

[0025] The first type of unlabeled nucleotides comprises a first hapten;

[0026] The second type of unlabeled nucleotides comprises a second hapten;

[0027] (c) contacting the extended copy polynucleotide with a set of affinity reagents under conditions where one of the affinity reagents specifically binds to the incorporated unlabeled nucleotide to provide a labeled extended copy polynucleotide;

[0028] (d) imaging the solid support and performing one or more fluorescence measurements of the extended copy polynucleotide; and

[0029] (e) removing the 3' blocking group of the incorporated nucleotide;

[0030] The affinity reagent comprises:

[0031] a first affinity reagent comprising a first hapten-binding partner capable of specifically binding to the first type of unlabeled nucleotides; and

[0032] a second affinity reagent comprising a second hapten binding partner capable of specifically binding to the second type of unlabeled nucleotides;

[0033] wherein the first affinity reagent comprises one or more first detectable labels, the one or more first detectable labels being capable of being excited by a first excitation light source, the second affinity reagent comprises one or more second detectable labels, the one or more second detectable labels being capable of being excited by a second excitation light source, and wherein the one or more first detectable labels are spectrally distinguishable from the one or more second detectable labels; and

[0034] wherein one of the first excitation light source and the second excitation light source has a wavelength of about 450 nm to about 460 nm, and the other of the first excitation light source and the second excitation light source has a wavelength of about 520 nm to about 540 nm;

[0035] In some embodiments of the kits or sequencing methods described herein, the kits and sequencing methods can reduce or eliminate sequence context effects or sequence specific effects, such as in two-channel synthesis sequencing (SBS). BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A dual-labeled protein assembly system according to an embodiment of the present disclosure is schematically shown.

[0037] Figure 2A Standard non-depolymerizable fluorescent nanoparticles are shown.

[0038] Figure 2B Depolymerizable labeled nanoparticles according to embodiments of the present disclosure are shown.

[0039] Figure 3A and Figure 3B is a scatter plot of a blue / green two-channel SBS run performed with an unlabeled nucleotide pool and a two-tag affinity reagent mixture according to two different embodiments of the present disclosure.

[0040] Figure 4A is a scatter plot of a blue / green two-channel SBS run performed with a pool of unlabeled nucleotides and a triple tag affinity reagent mixture according to one embodiment of the present disclosure.

[0041] Figure 4Bis a scatter plot of a blue / green two-channel SBS run using a universal ffN mixture and a three-tag affinity reagent mixture, wherein one of the affinity reagents is a dual-protein assembly system according to an embodiment of the present disclosure.

[0042] Figure 5A and Figure 5B is a graph of relative fluorescence intensity in solution, comparing ffA labeled with standard coumarin dye C and affinity reagents labeled with coumarin dye I-1 and dye I-2, respectively.

[0043] FIG. 6A to FIG. 6C It is the blue / green channel at loop 5 Scatter plot of SBS runs comparing a nucleotide set comprising fully functionalized C nucleotides (ffC) labeled with coumarin dye C to a nucleotide set comprising ffC labeled with dye 1-1 or dye 1-2.

[0044] Fig. 7A and Figure 7B is a bar graph showing the standard two-channel The percentage of T detection signal remaining after 151 cycles of SBS was compared between the standard coumarin dye C labeled as ffC and ffC labeled as dye I-2 or dye I-4, respectively, spiked into the mixture. DETAILED DESCRIPTION

[0045] definition

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The use of the term "include" as well as other forms such as "include / includes / included" is not restrictive. The use of the term "have" as well as other forms such as "have / has / had" is not restrictive. As used in this specification, the terms "comprise" and "includes" are to be interpreted as having an open-ended meaning, whether in a transitional phrase or in the body of the claims. That is, the above terms are to be interpreted synonymously with the phrases "at least have" or "at least include". For example, when used in the context of a process, the term "comprises" means that the process includes at least the listed steps, but may also include additional steps. When used in the context of a compound, composition, or device, the term "comprises" means that the compound, composition, or device includes at least the listed features or components, but may also include additional features or components.

[0047] As used herein, common organic abbreviations are defined as follows:

[0048] ℃ Temperature in degrees Celsius

[0049] dATP deoxyadenosine triphosphate

[0050] dCTP deoxycytidine triphosphate

[0051] dGTP deoxyguanosine triphosphate

[0052] dTTP deoxythymidine triphosphate

[0053] ddNTP dideoxynucleotide triphosphate

[0054] ffA fully functionalized A nucleotide

[0055] ffC fully functionalized C nucleotide

[0056] ffG fully functionalized G nucleotide

[0057] ffN Fully functionalized nucleotides

[0058] ffT fully functionalized T nucleotide

[0059] LED Light Emitting Diode

[0060] SBS Sequencing by Synthesis

[0061] As used herein, the term "array" refers to a group of different probe molecules connected to one or more substrates so that these different probe molecules can be distinguished from each other according to relative position. The array may include different probe molecules at different addressable positions on the substrate. Alternatively or additionally, the array may include a separate substrate with different probe molecules, wherein different probe molecules can be identified according to the position of the substrate on the surface to which the substrate is connected or according to the position of the substrate in the liquid. The exemplary array in which the separate substrate is located on the surface includes but is not limited to those comprising beads in the hole, such as, for example, U.S. Patent No. 6,355,431B1, US2002 / 0102578 and PCT disclose described in No. WO 00 / 63437. For example, in U.S. Patent No. 6,524,793, it is described that the exemplary form of beads in the liquid array can be used for example using a microfluidic device, such as a fluorescence activated cell sorter (FACS) is distinguished in the present invention. Additional examples of arrays that can be used in the present invention include, but are not limited to, U.S. Patent Nos. 5,429,807; 5,436,327; 5,561,071; 5,583,211; 5,658,734; 5,837,858; 5,874,219; 5,919,523; 6,136,269; No. 6,287,768; No. 6,287,776; No. 6,288,220; No. 6,297,006; No. 6,291,193; No. 6,346,413; No. 6,416,949; No. 6,482,591; No. 6,514,751 and No. 6,610,482; and those described in WO93 / 17126; WO 95 / 11995; WO 95 / 35505; EP 742287; and EP 799 897.

[0062] As used herein, the term "covalently attached" or "covalently bonded" refers to the formation of a chemical bond characterized by the sharing of electron pairs between atoms. For example, a covalently attached polymer coating refers to a polymer coating that forms a chemical bond with a functionalized surface of a substrate, as opposed to adhering to the surface via other means (e.g., adhesion or electrostatic interactions). It should be understood that a polymer covalently attached to a surface may also be bonded via means other than covalent attachment.

[0063] As used herein, the term "non-covalent interaction" differs from a covalent bond in that it does not involve sharing electrons, but rather involves more dispersed changes in electromagnetic interactions between or within molecules. Non-covalent interactions can generally be divided into four categories: electrostatic effects, π effects, van der Waals forces, and hydrophobic effects. Non-limiting examples of electrostatic interactions include ionic interactions, hydrogen bonding (a specific type of dipole-dipole interaction), halogen bonding, etc. Van der Waals forces are a subset of electrostatic interactions involving permanent or induced dipoles or multipoles. The π effect can be broken down into many categories, including (but not limited to) π-π interactions, cation-π and anion-π interactions, and polar-π interactions. Generally speaking, the π effect is related to the interaction of molecules with the π-orbitals of molecular systems (such as benzene). The hydrophobic effect is the tendency of non-polar substances to aggregate in aqueous solutions and repel water molecules. Non-covalent interactions can be intermolecular and intramolecular. Non-covalent interactions can be intermolecular and intramolecular.

[0064] It is understood that certain group naming conventions may include either a monoradical or a diradical, depending on the context. For example, when a substituent requires two points of attachment to the rest of the molecule, it is understood that the substituent is a diradical. For example, a substituent identified as an alkyl group requiring two points of attachment includes a diradical, such as -CH2-, -CH2CH2-, -CH2CH(CH3)CH2-, etc. Other group naming conventions clearly indicate that the group is a diradical, such as "alkylene" or "alkenylene".

[0065] As used herein, the term "halogen" or "halo" means any of the radioactive stable atoms of column 7 of the periodic table, for example, fluorine, chlorine, bromine or iodine, with fluorine and chlorine being preferred.

[0066] As used herein, "C" wherein "a" and "b" are integers a -C b ”, “C a -C b ” or “C a-b" refers to the number of carbon atoms in an alkyl, alkenyl, or alkynyl group, or the number of ring atoms in a cycloalkyl or aryl group. That is, the rings of alkyl, alkenyl, alkynyl, cycloalkyl, and aryl groups can contain from "a" to "b" (inclusive) carbon atoms. For example, a "C1 to C4 alkyl" group refers to all alkyl groups having from 1 to 4 carbons, i.e., CH3-, CH3CH2-, CH3CH2CH2-, (CH3)2CH-, CH3CH2CH2 CH2-, CH3CH2CH(CH3)- and (CH3)3C-; C3 to C4 cycloalkyl groups refer to all cycloalkyl groups having 3 to 4 carbon atoms, i.e., cyclopropyl and cyclobutyl. Similarly, a "4 to 6 membered heterocyclyl" group refers to all heterocyclyl groups having 4 to 6 total ring atoms, such as azetidine, oxetane, oxazoline, pyrrolidine, piperidine, piperazine, morpholine, etc. If there is no alkyl, alkenyl, alkynyl, cycloalkyl or aryl group, the alkyl group may be used. If "a" and "b" are specified, the broadest range described in these definitions will be assumed. As used herein, the term "C1-C6" includes C1, C2, C3, C4, C5, and C6, as well as ranges defined by either of these two numbers. For example, C1-C6 alkyl includes C1 alkyl, C2 alkyl, C3 alkyl, C4 alkyl, C5 alkyl, and C6 alkyl, C2-C6 alkyl, C1-C3 alkyl, etc. Similarly, C2-C6 alkenyl includes C2 alkenyl, C3 alkenyl, C4 alkenyl, C5 alkenyl, and C6 alkenyl. C3-C8 cycloalkyl groups include hydrocarbon rings containing 3, 4, 5, 6, 7 and 8 carbon atoms or ranges defined by any two numbers, such as C3-C7 cycloalkyl groups or C5-C6 cycloalkyl groups.

[0067] As used herein, "alkyl" refers to a straight or branched hydrocarbon chain that is fully saturated (i.e., does not contain double bonds and triple bonds). The alkyl group may have 1 to 20 carbon atoms (whenever it appears in this article, a numerical range such as "1 to 20" refers to each integer in the given range; for example, "1 to 20 carbon atoms" means that the alkyl group may be composed of 1 carbon atom, 2 carbon atoms, 3 carbon atoms, etc., up to and including 20 carbon atoms, but this definition also covers the term "alkyl" in which no numerical range is specified). The alkyl group may also be a medium-sized alkyl group with 1 to 9 carbon atoms. The alkyl group may also be a low-alkyl group with 1 to 6 carbon atoms. The alkyl group may be named "C1-C4 alkyl" or a similar name. By way of example only, "C 1-"C6 alkyl" means that there are one to six carbon atoms in the alkyl chain, that is, the alkyl chain is selected from the group consisting of methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl and tert-butyl. Typical alkyl groups include, but are by no means limited to, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, hexyl, and the like.

[0068] As used herein, "alkoxy" refers to a radical of the formula -OR (wherein R is an alkyl radical as defined above), such as "C 1- "C9 alkoxy" includes, but is not limited to, methoxy, ethoxy, n-propoxy, 1-methylethoxy (isopropoxy), n-butoxy, isobutoxy, sec-butoxy and tert-butoxy, etc.

[0069] As used herein, "alkenyl" refers to a straight or branched hydrocarbon chain containing one or more double bonds. An alkenyl group may have from 2 to 20 carbon atoms, but this definition also encompasses the term "alkenyl" where no numerical range is specified. An alkenyl group may also be a medium-sized alkenyl group having from 2 to 9 carbon atoms. An alkenyl group may also be a lower alkenyl group having from 2 to 6 carbon atoms. An alkenyl group may be designated as "C 2- C6 alkenyl" or similar designations. By way of example only, "C 2- "C6 alkenyl" means that there are two to six carbon atoms in the alkenyl chain, that is, the alkenyl chain is selected from the group consisting of ethenyl, propen-1-yl, propen-2-yl, propen-3-yl, buten-1-yl, buten-2-yl, buten-3-yl, buten-4-yl, 1-methyl-propen-1-yl, 2-methyl-propen-1-yl, 1-ethyl-ethen-1-yl, 2-methyl-propen-3-yl, buta-1,3-dienyl, buta-1,2-dienyl and buta-1,2-dien-4-yl. Typical alkenyl groups include, but are by no means limited to, ethenyl, propenyl, butenyl, pentenyl and hexenyl, etc.

[0070] The term "aromatic" refers to a ring or ring system having a conjugated π electron system, and includes both carbocyclic aromatic groups (e.g., phenyl) and heterocyclic aromatic groups (e.g., pyridine). The term includes monocyclic groups or fused-ring polycyclic (i.e., rings that share adjacent pairs of atoms) groups, provided that the entire ring system is aromatic.

[0071] As used herein, "aryl" refers to an aromatic ring or ring system (i.e., two or more fused rings that share two adjacent carbon atoms) that contains only carbon in the ring backbone. When aryl is a ring system, each ring in the ring system is aromatic. Aryl groups can have 6 to 18 carbon atoms, but this definition also covers the term "aryl" that appears without a specified numerical range. In some embodiments, aryl groups have 6 to 10 carbon atoms. Aryl groups can be designated as "C6-C 10 Aryl", "C6 or C 10Examples of aryl groups include, but are not limited to, phenyl, naphthyl, azulenyl, and anthracenyl.

[0072] "Aralkyl" or "arylalkyl" is an aryl group attached as a substituent through an alkylene group, such as "C 7-14 "Aralkyl" and the like, including but not limited to benzyl, 2-phenylethyl, 3-phenylpropyl and naphthylalkyl. In some cases, the alkylene group is a lower alkylene group (i.e., C 1- C6 alkylene group).

[0073] As used herein, "aryloxy" refers to RO-, where R is aryl as defined above, such as but not limited to phenyl.

[0074] As used herein, "heteroaryl" refers to an aromatic ring or ring system (i.e., two or more condensed rings sharing two adjacent atoms) containing one or more heteroatoms (i.e., elements other than carbon, including but not limited to nitrogen, oxygen and sulfur) in the ring skeleton. When heteroaryl is a ring system, each ring in the ring system is aromatic. The heteroaryl group can have 5 to 18 ring members (i.e., the number of atoms (including carbon atoms and heteroatoms) constituting the ring skeleton), but the present definition also encompasses the term "heteroaryl" in which no numerical range is specified. In some embodiments, the heteroaryl group has 5 to 10 ring members or 5 to 7 ring members. The heteroaryl group can be named "5 to 7 yuan heteroaryl", "5 to 10 yuan heteroaryl" or similar names. Examples of heteroaryl rings include, but are not limited to, furanyl, thienyl, phthalazinyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, pyrazolyl, isoxazolyl, isothiazolyl, triazolyl, thiadiazolyl, pyridinyl, pyridazinyl, pyrimidinyl, pyrazinyl, triazinyl, quinolyl, isoquinolyl, benzimidazolyl, benzoxazolyl, benzothiazolyl, indolyl, isoindolyl, and benzothiophenyl.

[0075] "Heteroaralkyl" or "heteroarylalkyl" is a heteroaryl group attached as a substituent via an alkylene group. Examples include, but are not limited to, 2-thienylmethyl, 3-thienylmethyl, furanylmethyl, thienylethyl, pyrrolylalkyl, pyridylalkyl, isoxazolylalkyl, and imidazolylalkyl. In some cases, the alkylene group is a lower alkylene group (i.e., C 1- C6 alkylene group).

[0076] As used herein, "carbocyclyl" means a non-aromatic cyclic ring or ring system containing only carbon atoms in the ring system skeleton. When the carbocyclyl is a ring system, two or more rings can be joined together in a fused, bridged or spiro manner. The carbocyclyl can have any degree of saturation, provided that at least one ring in the ring system is not aromatic. Therefore, carbocyclyl includes cycloalkyl, cycloalkenyl and cycloalkynyl. The carbocyclyl group can have 3 to 20 carbon atoms, but this definition also covers the term "carbocyclyl" in which no numerical range is specified. The carbocyclyl group can also be a medium-sized carbocyclyl with 3 to 10 carbon atoms. The carbocyclyl group can also be a carbocyclyl with 3 to 6 carbon atoms. The carbocyclyl group can be named "C 3- C6 carbocyclyl" or similar designations. Examples of carbocyclyl rings include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclohexenyl, 2,3-dihydro-indene, bicyclo[2.2.2]octanyl, adamantyl, and spiro[4.4]nonanyl.

[0077] As used herein, "cycloalkyl" means a fully saturated carbocyclyl ring or ring system. Examples include cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl.

[0078] As used herein, "heterocyclyl" refers to a non-aromatic cyclic ring or ring system containing at least one heteroatom in the ring backbone. The heterocyclyl group can be joined together in a fused, bridged or spiro manner. The heterocyclyl group can have any degree of saturation, provided that at least one ring in the ring system is not aromatic. The heteroatom can be present in a non-aromatic ring or an aromatic ring in the ring system. The heterocyclyl group can have 3 to 20 ring members (i.e., the number of atoms (including carbon atoms and heteroatoms) constituting the ring backbone), but this definition also covers the term "heterocyclyl" in which no numerical range is specified. The heterocyclyl group can also be a medium-sized heterocyclyl group with 3 to 10 ring members. The heterocyclyl group can also be a heterocyclyl group with 3 to 6 ring members. The heterocyclyl group can be named "3 to 6-membered heterocyclyl" or similar names. In preferred six-membered monocyclic heterocyclyls, the heteroatoms are selected from one to a maximum of three from O, N or S, and in preferred five-membered monocyclic heterocyclyls, the heteroatoms are selected from one or two heteroatoms selected from O, N or S. Examples of heterocyclyl rings include, but are not limited to, azepinyl, acridinyl, carbazolyl, cinnolinyl, dioxolanyl, imidazolinyl, imidazolidinyl, morpholinyl, oxiranyl, oxepanyl, thiepanyl, piperidinyl, piperazinyl, dioxopiperazinyl, pyrrolidinyl, pyrrolidonyl, pyrrolidinedionyl, 4-piperidonyl, pyrazolinyl, pyrazolidinyl, 1,3-dioxinyl, 1,3-dioxinyl, 1,4-dioxinyl, 1,4-dioxinyl, 1,3-oxathianyl, 1,4-oxathianyl, 1,4-oxathianyl, 2 H-1,2-oxazinyl, trioxanyl, hexahydro-1,3,5-triazinyl, 1,3-dioxolyl, 1,3-dioxolanyl, 1,3-dithienyl, 1,3-dithianyl, isoxazolinyl, isoxazolidinyl, oxazolinyl, oxazolidinyl, oxazolidinone, thiazolinyl, thiazolidinyl, 1,3-oxathiolanyl, indolinyl, isoindolinyl, tetrahydrofuranyl, tetrahydropyranyl, tetrahydrothienyl, tetrahydrothiopyranyl, tetrahydro-1,4-thiazinyl, thiomorpholinyl, dihydrobenzofuranyl, benzimidazolidinyl and tetrahydroquinoline.

[0079] As used herein, "(aryl)alkyl" refers to an aryl group as defined above attached as a substituent via an alkylene group as described above. The alkylene and aryl groups of the aralkyl group may be substituted or unsubstituted. Examples include, but are not limited to, benzyl, 2-phenylalkyl, 3-phenylalkyl, and naphthylalkyl. In some embodiments, the alkylene group is an unsubstituted straight chain containing 1, 2, 3, 4, 5, or 6 methylene units.

[0080] As used herein, "(heteroaryl)alkyl" refers to a heteroaryl group as defined above attached as a substituent via an alkylene group as defined above. The alkylene and heteroaryl groups of the heteroaralkyl group may be substituted or unsubstituted. Examples include, but are not limited to, 2-thienylalkyl, 3-thienylalkyl, furanylalkyl, thienylalkyl, pyrrolylalkyl, pyridylalkyl, isoxazolylalkyl, and imidazolylalkyl, and their benzo-fused analogs. In some embodiments, the alkylene group is an unsubstituted straight chain containing 1, 2, 3, 4, 5, or 6 methylene units.

[0081] As used herein, "(heterocyclyl)alkyl" refers to a heterocycle or heterocyclyl group as defined above connected as a substituent via an alkylene group as defined above. The alkylene group and heterocyclyl group of the (heterocyclyl)alkyl can be substituted or unsubstituted. Examples include, but are not limited to, (tetrahydro-2H-pyran-4-yl)methyl, (piperidin-4-yl)ethyl, (piperidin-4-yl)propyl, (tetrahydro-2H-thiopyran-4-yl)methyl and (1,3-thiazin-4-yl)methyl. In some embodiments, the alkylene group is an unsubstituted straight chain containing 1, 2, 3, 4, 5 or 6 methylene units.

[0082] As used herein, "(carbocyclyl)alkyl" refers to a carbocyclyl group (as defined herein) attached as a substituent via an alkylene group. Examples include, but are not limited to, cyclopropylmethyl, cyclobutylmethyl, cyclopentylethyl, and cyclohexylpropyl. In some embodiments, the alkylene group is an unsubstituted straight chain containing 1, 2, 3, 4, 5, or 6 methylene units.

[0083] As used herein, "alkoxyalkyl" or "(alkoxy)alkyl" refers to an alkoxy group attached through an alkylene group, such as C2-C8alkoxyalkyl or (C1-C6alkoxy)C1-C6alkyl, for example -(CH2) 1-3 -OCH3.

[0084] As used herein, "-O-alkoxyalkyl" or "-O-(alkoxy)alkyl" refers to an alkoxy group attached via an -O-(alkylene) group, such as -O-(C1-C6alkoxy)C1-C6alkyl, e.g. -O-(CH2) 1-3 -OCH3.

[0085] As used herein, "haloalkyl" refers to an alkyl group in which one or more hydrogen atoms are replaced by a halogen (e.g., monohaloalkyl, dihaloalkyl, and trihaloalkyl). Such groups include, but are not limited to, chloromethyl, fluoromethyl, difluoromethyl, trifluoromethyl, and 1-chloro-2-fluoromethyl, 2-fluoroisobutyl. The haloalkyl group may be substituted or unsubstituted.

[0086] As used herein, "haloalkoxy" refers to an alkoxy group in which one or more hydrogen atoms are replaced by a halogen (e.g., monohaloalkoxy, dihaloalkoxy, and trihaloalkoxy). Such groups include, but are not limited to, chloromethoxy, fluoromethoxy, difluoromethoxy, trifluoromethoxy, and 1-chloro-2-fluoromethoxy, 2-fluoroisobutoxy. The haloalkoxy group may be substituted or unsubstituted.

[0087] An "amino" group refers to a -NH2 group. As used herein, the term "monosubstituted amino group" refers to an amino (-NH2) group in which one hydrogen atom is replaced by a substituent. As used herein, the term "disubstituted amino group" refers to an amino (-NH2) group in which each of the two hydrogen atoms is replaced by a substituent. As used herein, the term "optionally substituted amino" refers to a -NR A R B Group, where R A and R B and R is independently hydrogen, alkyl, cycloalkyl, aryl, heteroaryl, heterocyclyl, aralkyl or heterocyclyl(alkyl), as defined herein.

[0088] An "O-carboxyl" group is one in which R is selected from hydrogen, C 1- C6 alkyl, C 2- C6 alkenyl, C 2- C6 alkynyl, C 3- C7 carbocyclic group, C 6- C 10 Aryl, 5- to 10-membered heteroaryl, and 3- to 10-membered heterocyclyl "-OC(=O)R" groups are as defined herein.

[0089] A "C-carboxyl" group is one in which R is selected from the group consisting of hydrogen, C 1- C6 alkyl, C 2- C6 alkenyl, C 2- C6 alkynyl, C 3- C7 carbocyclic group, C 6- C 10 The "-C(=O)OR" group of the group consisting of aryl, 5- to 10-membered heteroaryl, and 3- to 10-membered heterocyclyl, as defined herein. Non-limiting examples include carboxyl (ie, -C(=O)OH).

[0090] A "sulfonyl" group is a group in which R is selected from hydrogen, C 1- C6 alkyl, C 2- C6 alkenyl, C 2- C6 alkynyl, C 3- C7 carbocyclic group, C 6- C 10 The "-SO2R" group of aryl, 5- to 10-membered heteroaryl and 3- to 10-membered heterocyclyl are as defined herein.

[0091] A "sulfinyl" group refers to a "-S(=O)OH" group.

[0092] A "sulfo" group refers to a "-S(=O)2OH" or a "-SO3H" group.

[0093] A "sulfonate" group refers to a "-SO3" group.

[0094] A "sulfate" group refers to a "-SO4ˉ" group.

[0095] An "S-sulfonamido" group refers to a group in which R A and R B are each independently selected from hydrogen, C 1- C6 alkyl, C 2- C6 alkenyl, C 2- C6 alkynyl, C 3- C7 carbocyclic group, C 6- C 10 "-SO2NR" of aryl, 5- to 10-membered heteroaryl and 3- to 10-membered heterocyclic group A R B " group, as defined herein.

[0096] An "N-sulfonamido" group is one in which R A and R B are each independently selected from hydrogen, C 1- C6 alkyl, C 2- C6 alkenyl, C 2- C6 alkynyl, C 3- C7 carbocyclic group, C 6- C 10 "-N(R)" of aryl, 5- to 10-membered heteroaryl and 3- to 10-membered heterocyclic group A )SO2R B " group, as defined herein.

[0097] A "C-amido" group is one in which R A and R B are each independently selected from hydrogen, C 1- C6 alkyl, C 2- C6 alkenyl, C 2- C6 alkynyl, C 3- C7 carbocyclic group, C 6- C 10 "-C(=O)NR" of aryl, 5- to 10-membered heteroaryl and 3- to 10-membered heterocyclic group A R B " group, as defined herein.

[0098] An "N-amido" group is one in which R A and R Bare each independently selected from hydrogen, C 1- C6 alkyl, C 2- C6 alkenyl, C 2- C6 alkynyl, C 3- C7 carbocyclic group, C 6- C 10 "-N(R)" of aryl, 5- to 10-membered heteroaryl and 3- to 10-membered heterocyclic group A )C(=O)R B " group, as defined herein.

[0099] An "O-carbamyl" group refers to a "-OC(=O)N(R A R B )" group, wherein R A and R B The same definition as for S-sulfonylamino may be used. The O-carbamyl group may be substituted or unsubstituted.

[0100] An "N-carbamyl" group refers to an "ROC(=O)N(R A ) - " group, where R and R A The same definition as for N-sulfonylamino may be used. The N-carbamoyl group may be substituted or unsubstituted.

[0101] An "O-thiocarbamyl" group refers to an "-OC(=S)-N(R A R B )" group, wherein R A and R B The O-thiocarbamoyl group may be substituted or unsubstituted.

[0102] An "N-thiocarbamyl" group refers to an "ROC(=S)N(R A )-" group, where R and R A The same definition as for N-sulfonylamino group may be used. The N-thiocarbamoyl group may be substituted or unsubstituted.

[0103] The term "alkylamino" or "(alkyl)amino" refers to an amino group in which one or both hydrogen atoms are replaced by an alkyl group.

[0104] An "(alkoxy)alkyl" group refers to an alkoxy group attached through an alkylene group, such as "(C 1- C6 alkoxy)C 1- C6 alkyl" etc.

[0105] The term "hydroxyl" as used herein refers to an -OH group.

[0106] The term "cyano" as used herein refers to a "-CN" group.

[0107] The term "azido" as used herein refers to a -N3 group.

[0108] As used herein, the term "isocyanide" refers to "-N + ≡Cˉ” group.

[0109] When a group is described as "optionally substituted," it may be unsubstituted or substituted. Likewise, when a group is described as "substituted," the substituents may be selected from one or more of the indicated substituents. As used herein, a substituted group is derived from an unsubstituted parent group in which there has been an exchange of one or more hydrogen atoms with another atom or group.Unless otherwise specified, when a group is considered to be "substituted", it means that the group is substituted by one or more substituents independently selected from the group consisting of C1-C6 alkyl, C1-C6 alkenyl, C1-C6 alkynyl, C1-C6 heteroalkyl, C3-C7 carbocyclyl (optionally substituted with halo, C1-C6 alkyl, C1-C6 alkoxy, C1-C6 haloalkyl and C1-C6 haloalkoxy), C3-C7 carbocyclyl-C1-C6-alkyl (optionally substituted with halo, C1-C6 alkyl, C1-C6 alkoxy, C1-C6 haloalkyl and C1-C6 haloalkoxy), 3-10 membered heterocyclyl (optionally substituted with halo, C1-C6 alkyl, C1-C6 alkoxy, C1-C6 haloalkyl and C1-C6 haloalkoxy), C1-C6-alkyl (optionally substituted with halo, C1-C6 alkyl, C1-C6 alkoxy, C1-C6 haloalkyl and C1-C6 haloalkoxy), 3-10 membered heterocyclyl-C1-C6-alkyl (optionally substituted with halo, C1-C6 alkyl, C1-C6 alkoxy, C1-C6 haloalkyl and C1-C6 haloalkoxy), aryl (optionally substituted with halo, C1-C6 alkyl, C1-C6 alkoxy, C1-C6 haloalkyl and C1-C6 haloalkoxy), (aryl)C1-C6 alkyl (optionally substituted with halo, C1-C6 alkyl, C1-C6 alkoxy, C1-C6 haloalkyl and C1-C6 haloalkoxy), C1-C6 alkyl, C1-C6 alkoxy, C1-C6 haloalkyl and C1-C6 haloalkoxy), (5-10 membered heteroaryl)C1-C6 alkyl (optionally substituted with halo, C1-C6 alkyl, C1-C6 alkoxy, C1-C6 haloalkyl and C1-C6 haloalkoxy), halo, -CN, hydroxy, C1-C6 alkoxy, (C1-C6 alkoxy)C1-C6 alkyl, -O(C1-C6 alkoxy)C1-C6 alkyl; (C1-C6 haloalkoxy)C1-C6 alkyl; -O(C1-C6 haloalkoxy) C1-C6 alkyl; aryloxy, thiol (sulfhydryl), halo(C1-C6)alkyl (e.g., –CF3), halo(C1-C6)alkoxy (e.g., –OCF3), C1-C6 alkylthio, arylthio, amino, amino(C1-C6)alkyl, nitro, O-carbamyl, N-carbamyl, O-thiocarbamyl, N-thiocarbamyl, C-acylamino, N-acylamino, S-sulfonylamino, N-sulfonylamino, C-carboxyl, O-carboxyl, acyl, cyanate, isocyanate, thiocyanate, isothiocyanate, sulfinyl, sulfonyl, -SO3H, sulfonate, sulfate, sulfinyl, -OSO2C. 1-4 Alkyl, monophosphate, diphosphate, triphosphate and oxo (=0). Wherever a group is described as "optionally substituted", the group may be substituted with the above substituents.

[0110] In each case where a single meso form of a compound described herein is shown, the alternative meso forms are also contemplated.

[0111] As used herein, "nucleotides" include nitrogenous heterocyclic bases, sugars, and one or more phosphate groups. They are monomeric units of nucleic acid sequences. In RNA, the sugar is ribose, and in DNA it is deoxyribose, i.e., a sugar lacking the hydroxyl groups present in ribose. The nitrogenous heterocyclic bases may be purines, deazapurines, or pyrimidine bases. Purine bases include adenine (A) and guanine (G) and their modified derivatives or analogs, such as 7-deazaadenine or 7-deazaguanine. Pyrimidine bases include cytosine (C), thymine (T), and uracil (U) and their modified derivatives or analogs. The C-1 atom of deoxyribose is bonded to the N-1 of pyrimidine or the N-9 of purine.

[0112] As used herein, "nucleotide conjugates" generally refer to nucleotides labeled with a fluorescent moiety, optionally labeled by a cleavable linker as described herein. In some embodiments, when a nucleotide complex is described as an unlabeled nucleotide, such nucleotide does not include a fluorescent moiety. In some additional embodiments, the unlabeled nucleotide conjugate also does not have a cleavable linker.

[0113] As used herein, "nucleoside" is structurally similar to a nucleotide, but lacks a phosphate moiety. An example of a nucleoside analog is a nucleoside analog in which a label is attached to a base and no phosphate group is attached to a sugar molecule. The term "nucleoside" is used herein in the conventional sense as understood by those skilled in the art. Examples include, but are not limited to, ribonucleosides comprising a ribose moiety and deoxyribonucleosides comprising a deoxyribose moiety. A modified pentose moiety is a pentose moiety in which an oxygen atom has been replaced by a carbon and / or a carbon has been replaced by a sulfur or oxygen atom. A "nucleoside" is a monomer that may have a substituted base and / or sugar moiety. In addition, nucleosides may be incorporated into larger DNA and / or RNA polymers and oligomers.

[0114] The term "purine base" is used herein with the common meaning understood by those skilled in the art, and includes its tautomers. Similarly, the term "pyrimidine base" is used herein with the common meaning understood by those skilled in the art, and includes its tautomers. The non-limiting list of optionally substituted purine bases includes purine, adenine, guanine, deazapurine, 7-deazaadenine, 7-deazaguanine, hypoxanthine, xanthine, alloxanthine, 7-alkylguanine (e.g., 7-methylguanine), theobromine, caffeine, uric acid, and isoguanine. The example of pyrimidine bases includes, but is not limited to, cytosine, thymine, uracil, 5,6-dihydrouracil, and 5-alkylcytosine (e.g., 5-methylcytosine).

[0115] As used herein, when oligonucleotide or polynucleotide are described as "comprising " nucleoside or nucleotide as described herein, this means that nucleoside or nucleotide as described herein forms covalent bond with oligonucleotide or polynucleotide.Similarly, when nucleoside or nucleotide are described as a part of oligonucleotide or polynucleotide, such as "being incorporated into " oligonucleotide or polynucleotide, this means that nucleoside or nucleotide as described herein forms covalent bond with oligonucleotide or polynucleotide.In some such embodiments, covalent bond is formed between 5' phosphate groups of the nucleotide of phosphodiester bond between 3' carbon atom of oligonucleotide or polynucleotide and 5' carbon atom of nucleotide described in this article.

[0116] As used herein, the term "cleavable linker" is not intended to imply that the entire linker needs to be removed. The cleavage site can be located at a position on the linker that ensures that a portion of the linker remains attached to the detectable label and / or nucleoside or nucleotide moiety after cleavage.

[0117] As used herein, "derivative" or "analog" means a synthetic nucleotide or nucleoside derivative with a modified base moiety and / or a modified sugar moiety. Such derivatives and analogs are discussed in, for example, Scheit, Nucleotide Analogs (John Wiley & Son, 1980) and Uhlman et al., Chemical Reviews 90: 543-584, 1990. Nucleotide analogs can also include modified phosphodiester bonds, including phosphorothioate bonds, phosphorodithioate bonds, alkylphosphonate bonds and phosphoramidate bonds. As used herein, "derivative", "analog" and "modified" are used interchangeably, and are covered by the terms "nucleotide" and "nucleoside" defined herein.

[0118] As used herein, a molecule containing a biotin moiety or an analog thereof comprises the structure In some cases, the biotin moiety is linked to the remainder of the molecule via a linker, such as Analogs of molecules containing a biotin moiety may include substituted biotin moieties.

[0119] As used herein, an alkyl chloride-containing molecule or its analog comprises the structure Analogs of molecules containing alkyl chloride moieties may include substituted alkyl chloride moieties.

[0120] As used herein, a molecule containing a dinitrophenyl (DNP) moiety or an analog thereof comprises the structure In some cases, the connection to the rest of the molecule is via a linker, such as Analogs of molecules containing a DNP moiety may include substituted DNP moieties.

[0121] As used herein, a molecule containing a digoxin (DIG) moiety or an analog thereof comprises the structure or its diastereoisomers, such as In some cases, the DIG moiety is linked to the remainder of the molecule via a linker, such as Analogs of molecules containing a DIG moiety may include substituted DIG moieties.

[0122] As used herein, a molecule containing a β-N-acetylglucosamine (O-GlcNAc) moiety or an analog thereof comprises the structure Analogs of molecules containing O-GlcNAc moieties may include substituted O-GlcNAc moieties.

[0123] As used herein, a molecule containing an alkylguanine moiety or an analog thereof comprises the structure Analogs of molecules containing alkylguanine moieties may include substituted alkylguanine moieties.

[0124] As used herein, a molecule containing a 3-nitrotyrosine moiety or an analog thereof comprises the structure Analogs of molecules containing a 3-nitrotyrosine moiety may include substituted 3-nitrotyrosine moieties.

[0125] As used herein, anti-DNP antibody refers to an antibody that is capable of specifically binding to the DNP moiety described herein.

[0126] As used herein, anti-DIG antibody refers to an antibody that is capable of specifically binding to the DIG moiety described herein.

[0127] As used herein, wheat germ agglutinin (WGA) refers to a lectin capable of binding to an O-GlcNAc moiety as described herein.

[0128] As used herein, SNAP-Tag refers to a commercially available protein tag. Capable of specifically binding to the alkylguanine moieties described herein.

[0129] As used herein, refers to commercially available protein tags. Capable of specifically binding to the alkyl chloride moieties described herein.

[0130] As used herein, anti-nitrotyrosine antibody refers to an antibody that is capable of specifically binding to the 3-nitrotyrosine moiety described herein.

[0131] As used herein, the term "phosphate" is used with its ordinary meaning as understood by those skilled in the art and includes its protonated forms (e.g., ). As used herein, the terms "monophosphate," "diphosphate," and "triphosphate" are used with their ordinary meaning as understood by those skilled in the art, and include protonated forms.

[0132] As will be appreciated by those of ordinary skill in the art, compounds described herein (such as nucleotide complexes) may exist in ionized form, e.g., containing -CO2-, -SO3 or -O-. If the compound contains a positively or negatively charged substituent group, it may also contain a negatively or positively charged counterion, such that the compound as a whole is neutral. In other aspects, the compound may exist in salt form, wherein the counterion is provided by a conjugate acid or base.

[0133] As used herein, the term "phasing" refers to a phenomenon in SBS, which is caused by incomplete removal of 3' terminators and fluorophores and / or failure to complete the incorporation of a portion of the DNA chain within the cluster by a polymerase under a given sequencing cycle. Prephasing is caused by the incorporation of nucleotides that do not have an effective 3' terminator, wherein the incorporation event is advanced by 1 cycle due to termination failure. Phasing and prephasing cause the measured signal intensity of a specific cycle to be composed of the signal from the current cycle and the noise from the previous and next cycles. As the number of cycles increases, the sequence score of each cluster affected by phasing and prephasing increases, hindering the identification of the correct base. Prephasing can be caused by the presence of traces of unprotected or uncapped 3'-OH nucleotides during sequencing by synthesis (SBS). Unprotected 3'-OH nucleotides can be produced during the manufacturing process or may be stored and during the reagent handling process.

[0134] As used herein, the term "sequence environment effect" or "sequence-specific effect" refers to the effect that the base intensity shown in the cloud-like scatter plot may be affected by the previous sequence environment during synthesis sequencing (SBS), especially two-channel SBS. This intensity modulation adds noise to the system, and when the sequence-specific intensity modulation shifts the intensity of a given cluster toward the decision boundary, it can cause false detection. It is also called sequence-specific error (SSE). Without being bound by a particular theory, one reason for the sequence-specific intensity shift is the differential incorporation of fully functionalized nucleotides (ffn) labeled with different dyes (e.g., green ffA and blue ffA). Another reason for the weakening of the fluorescence signal intensity may be that the labeled nucleotides incorporated by the aforementioned base pairs show different effects (e.g., quenching or enhancing the dye signal intensity). As described in the present disclosure, using a single fully functionalized nucleotide (ffN) in combination with an affinity reagent that can produce color in two channels can reduce or eliminate sequence-specific intensity shifts, and thereby improve base detection accuracy.

[0135] Reagent test kit

[0136] One aspect of the present disclosure relates to a kit for sequencing applications, the kit comprising:

[0137] a first type of unlabeled nucleotides comprising a first hapten;

[0138] a second type of unlabeled nucleotides comprising a second hapten;

[0139] a third type of unlabeled nucleotides; and

[0140] A set of affinity reagents, the set of affinity reagents comprising:

[0141] A first affinity reagent comprises an unlabeled

[0142] A first hapten binding partner that specifically binds to the nucleotide; and

[0143] a second affinity reagent comprising a second hapten binding partner capable of specifically binding to the second type of unlabeled nucleotides;

[0144] wherein the first affinity reagent comprises one or more first detectable labels, the one or more first detectable labels are capable of being excited by a first excitation light source, the second affinity reagent comprises one or more second detectable labels, the one or more second detectable labels are capable of being excited by a second excitation light source, and wherein the first detectable label is spectrally distinguishable from the second detectable label; and

[0145] wherein one of the first excitation light source and the second excitation light source has a wavelength of about 450 nm to about 460 nm, and the other of the first excitation light source and the second excitation light source has a wavelength of about 520 nm to about 540 nm;

[0146] In some embodiments of the kits described herein, the first hapten is covalently linked to the nucleobase of the first type of unlabeled nucleotide via a cleavable linker.

[0147] In some embodiments of the kits described herein, the second hapten is covalently linked to the nucleobase of the second type of unlabeled nucleotide via a cleavable linker.

[0148] Two-label system

[0149] In some embodiments of the kit described herein, the third type of unlabeled nucleotides comprises a mixture of the third type of unlabeled nucleotides containing the first hapten and the third type of unlabeled nucleotides containing the second hapten, and wherein the first affinity reagent and the second affinity reagent are both capable of specifically binding to the third type of unlabeled nucleotides. In yet another embodiment, each of the first hapten and the second hapten is covalently linked to the nucleobase of the third type of nucleotide via a cleavable linker. In yet another embodiment, the first hapten comprises a biotin moiety, and the first hapten binding partner comprises avidin (e.g., streptavidin, neutravidin, chrysoprolol, etc.). In yet another embodiment, the avidin is streptavidin. In yet another embodiment, the avidin is neutravidin. In yet another embodiment, one or more biotin binding sites of the avidin are capped by a molecule containing a biotin moiety or an analog thereof. In yet another embodiment, all remaining biotin binding sites of the avidin are capped by a molecule containing a biotin moiety or an analog thereof. In yet another embodiment, the second hapten comprises a dinitrophenyl (DNP) moiety, and the second hapten binding partner comprises an anti-DNP antibody. In some such embodiments, the third type of unlabeled nucleotides comprises a mixture of unlabeled nucleotides of the third type containing a biotin moiety and unlabeled nucleotides of the third type containing a DNP moiety. In another embodiment, the second hapten comprises a digoxigenin (DIG) moiety, and the second hapten binding partner comprises an anti-DIG antibody. In some such embodiments, the third type of unlabeled nucleotides comprises a mixture of unlabeled nucleotides of the third type containing a biotin moiety and unlabeled nucleotides of the third type containing a DIG moiety.

[0150] Three-label system

[0151] In some embodiments of the kit described herein, the third type of unlabeled nucleotides comprises a third hapten, and the set of affinity reagents further comprises a third affinity reagent, the third affinity reagent comprising a third hapten binding partner capable of specifically binding to the third hapten. In yet another embodiment, the third hapten is covalently linked to the nucleobase of the third type of unlabeled nucleotides via a cleavable linker. In yet another embodiment, the first hapten comprises a biotin moiety, and the first hapten binding partner comprises avidin. In yet another embodiment, the avidin is streptavidin. In yet another embodiment, the avidin is neutravidin. In yet another embodiment, one or more biotin binding sites of the avidin are capped with a molecule containing a biotin moiety or an analog thereof. In other additional embodiments, all remaining biotin binding sites of the avidin are capped with a molecule containing a biotin moiety or an analog thereof. In some such embodiments, one of the second hapten and the third hapten comprises a DNP moiety, and the other of the second hapten and the third hapten comprises a DIG moiety. In another embodiment, one of the first hapten and the second hapten comprises a DNP portion, and the other of the first hapten and the second hapten comprises a DIG portion. In some such embodiments, the third hapten comprises a biotin portion, and the third hapten binding partner comprises avidin. In yet another embodiment, the avidin is streptavidin. In yet another embodiment, the avidin is neutravidin. In yet another embodiment, one or more biotin binding sites of the avidin are capped with a molecule containing a biotin portion or an analog thereof. In other additional embodiments, all remaining biotin binding sites of the avidin are capped with a molecule containing a biotin portion or an analog thereof. In yet another embodiment, the third affinity reagent comprises one or more first detectable labels and one or more second detectable labels.

[0152] In some embodiments, the detectable label is covalently attached to the affinity reagent by reacting the functional group of the detectable label with the functional group of the hapten binding partner (e.g., a protein tag or an antibody). For example, the carboxyl group of the detectable label can react with the amino group of the hapten binding partner (e.g., an amino group of an amino acid portion of a protein or an antibody) to form an amide bond. In one example, one or more fluorescent dyes are covalently attached to one or more lysine moieties on a protein / antibody (e.g., streptavidin). In some embodiments, the average number of detectable labels on a protein / antibody is measured by comparing the absorption wavelength of the protein / antibody (e.g., absorbance at 280 nm) to the ratio of the detectable label (e.g., a fluorescent dye). In some embodiments, the average molar ratio of the first detectable label to the second detectable label can be between about 10: 1, 9.5: 1, 9: 1, 8.5: 1, 8: 1, 7.5: 1, 7: 1, 6.5: 1, 6: 1, 5.5: 1, 5: 1, 4.5: 1, 4: 1, 3.5: 1, 3: 1, 2.5: 1, 2: 1, 1.5: 1, 1: 1, 1: 1.5, 1: 2, 1: 2.5, 1: 3, 1: 3.5, 1: 4, 1.4.5, 1: 5, 1: 5.5, 1: 6, 1: 6.5, 1: 7, 1: 7.5, 1: 8, 1: 8.5, 1: 9, 1: 9.5, and 1: 10. In yet another embodiment, the third affinity reagent comprises a multi-dye labeled protein assembly system as described herein.

[0153] In addition to the conductive biotin-avidin (e.g., streptavidin or neutravidin), DNP / anti-DNP and DIG / anti-DIG pairs described herein, other haptens and hapten binding partners can also be used in the two-label system or three-label system described herein. Table 1 lists non-limiting examples of haptens and hapten binding partners.

[0154] Table 1. Illustrative examples of haptens and hapten binding partners.

[0155]

[0156] In any of the embodiments of the kits described herein, the concentration of each affinity reagent (e.g., a labeled protein tag or a labeled antibody) in the affinity reagent mixture can independently range from about 0.01 μM to about 1 μM, about 0.02 μM to about 0.5 μM, or about 0.05 μM to about 0.25 μM. In additional embodiments, the concentration of the affinity agent may independently be about 0.01 μM, 0.02 μM, 0.03 μM, 0.04 μM, 0.05 μM, 0.06 μM, 0.07 μM, 0.08 μM, 0.09 μM, 0.11 μM, 0.12 μM, 0.13 μM, 0.14 μM, 0.15 μM, 0.16 μM, 0.17 μM, 0.18 μM, 0.19 μM, 0.20 μM, 0.22 μM, 0.24 μM, 0.26 μM, 0.28 μM, 0.30 μM, 0.35 μM, 0.40 μM, 0.45 μM or 0.50 μM, or a range bounded by any two of the foregoing values.

[0157] In any embodiment of the kit described herein, the kit further comprises a fourth type of unlabeled nucleotides, wherein the fourth type of unlabeled nucleotides cannot specifically bind to any of the affinity reagents. In yet another embodiment, the fourth type of unlabeled nucleotides cannot be excited by the first light source or the second light source.

[0158] In any embodiment of the kit described herein, each of the first type of unlabeled nucleotide, the second type of unlabeled nucleotide, the third type of unlabeled nucleotide, and the fourth type of unlabeled nucleotide comprises a 3' capping group as described herein. For example, the 3' capping group may be an azidomethyl group (—CH2N3) attached to the 3' oxygen of the nucleotide. For another example, the 3' capping group may be —OCH2OCH2CH=CH2 (AOM) attached to the 3' carbon of the nucleotide. For another example, the 3' capping group may be an allyl group (—CH2CH=CH2) attached to the 3' oxygen of the nucleotide.

[0159] In any embodiment of the kit described herein, any one or more of the first hapten, the second hapten, or the third hapten may be covalently linked to the nucleotide via a cleavable linker described herein. In some embodiments, the cleavable linker may contain one or more azido moieties, one or more allyl moieties, or a combination thereof. The linker may also contain a spacer, such as PEG. In additional embodiments, the cleavable linker may be cleaved under the same reaction conditions as the 3' capping group.

[0160] In any embodiment of the test kit described herein, the test kit may also include an archaeal dna polymerase and one or more buffer compositions. In other embodiments, the test kit may include one or more unlabeled nucleotides of non-dark G. For example, the test kit may include one or more unlabeled T nucleotides to weaken the green T signal. Alternatively or additionally, the test kit may include one or more labeled nucleotides, wherein the labeled nucleotides may contain a fluorescent label that cannot be excited by the first light source or the second light source.

[0161] Detectable Tags

[0162] A. Protein Assembly System

[0163] One aspect of the present disclosure relates to a protein assembly system comprising:

[0164] a first protein labeled with one or more first detectable labels;

[0165] one or more hapten-containing linkers, the one or more hapten-containing linkers being covalently attached to the first protein; and

[0166] one or more hapten-binding second proteins, the one or more hapten-binding second proteins being conjugated to one or more hapten-containing linkers;

[0167] wherein the one or more hapten-bound second proteins are labeled with one or more second detectable labels, and wherein the one or more first detectable labels are spectrally distinguishable from the one or more second detectable labels.

[0168] In some embodiments of the protein assembly systems described herein, the one or more hapten-bound second proteins are bound to the one or more hapten-containing linkers via non-covalent interactions; in other embodiments, the one or more hapten-bound second proteins are bound to the one or more hapten-containing linkers via covalent interactions; in some additional embodiments, the one or more hapten-containing linkers are linkers containing a biotin moiety, and the one or more hapten-bound second proteins are biotin-binding proteins. In yet another embodiment, the one or more hapten-bound second proteins comprise avidin. In yet another embodiment, the avidin is streptavidin. In yet another embodiment, the avidin is neutravidin. In yet another embodiment, the one or more biotin-binding sites of the avidin are capped with a molecule containing a biotin moiety or an analog thereof. In yet further embodiments, all remaining biotin-binding sites of the avidin are capped with a molecule containing a biotin moiety or an analog thereof.

[0169] In some embodiments of the protein assembly systems described herein, the first protein comprises an antibody. In other embodiments, the antibody is an anti-DNP antibody or an anti-DIG antibody.

[0170] In some embodiments of the protein assembly system described herein, the one or more first detectable labels can be excited by blue light, and the one or more second detectable labels can be excited by green light. In some such embodiments, the one or more first detectable labels include or are selected from the coumarin dyes with the structure of formula (I) as described herein. In another embodiment, the one or more first detectable labels can be excited by green light, and the one or more second detectable labels can be excited by blue light. In other embodiments, the blue light has a wavelength of about 450nm to about 460nm. In other embodiments, the green light has a wavelength of about 520nm to about 540nm (e.g., about 532nm).

[0171] In some embodiments of the protein assembly systems described herein, the first protein is labeled with a plurality of first detectable labels. In other embodiments, the first protein is labeled with at least three, at least four, at least five, at least six, at least seven, at least eight, at least nine, or at least ten first detectable labels.

[0172] In some embodiments of the protein assembly system, wherein the system includes at least two biotin-binding proteins (e.g., three biotin-binding proteins), each biotin-binding protein is labeled with a plurality of second detectable labels. In other embodiments, each biotin-binding protein is labeled with at least three, at least four, at least five, at least six, at least seven, at least eight, at least nine, or at least ten second detectable labels. In other embodiments, one or more biotin-binding proteins in the biotin-binding protein may comprise avidin. In yet another embodiment, the avidin is streptavidin. In yet another embodiment, the avidin is neutravidin.

[0173] In some embodiments of the protein assembly system, the biotin-containing linker comprises a PEG repeating unit (—OCH2CH2—) n , wherein n is an integer from 2 to 30. In some embodiments, n is 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15.

[0174] Figure 1The double protein assembly system according to the embodiment of the present disclosure is schematically shown. The first protein can be an antibody (e.g., anti-DNP or anti-DIG antibody) with one or more first detectable labels. The first detectable label can include, for example, a first dye portion. The first protein can be labeled with one, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen or fifteen detectable labels, although in some embodiments, more detectable labels can be included. One or more hapten-containing joints can be joints containing biotin moieties. One or more biotin-containing joints can be covalently attached to the first protein. For example, one, two, three, four, five, six, seven, eight, nine or ten joints containing biotin moieties can be covalently attached to the first protein, although in some embodiments, more biotin joints can be attached to the first protein / antibody. The second protein to which one or more hapten bonds can include one or more second detectable labels. For example, according to the present embodiment, the second protein to which one or more hapten bonds can include or be an avidin molecule, such as streptavidin or neutravidin. The second detectable label can include a second dye portion. The first dye part and the second dye part can have different excitation and fluorescence emission wavelengths, so that the emission fluorescence of the first dye part and the emission fluorescence of the second dye part are spectrally distinguishable. In some embodiments, the first detectable label can include "blue dye", which can be excited by a blue light source with a wavelength between about 450nm and about 460nm. In some other embodiments, the second detectable label can include "green dye", which can be excited by a green light source with a wavelength between about 520nm and about 540nm. The avidin molecule of the mark can be introduced and attached to the biotin part, which contains the joint connected to the first protein / antibody. Therefore, the protein assembly system can include a plurality of first detectable labels and a plurality of second detectable labels. In other embodiments, the molar ratio of the first protein / antibody to the second protein (e.g., avidin / streptavidin / neutravidin) may be between about 10:1, 9:1, 8:1, 7:1, 6:1, 5:1, 4:1, 3:1, 2:1, 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, and 1:10. In some embodiments, the molar ratio of the first protein / antibody to the second protein is calculated by the molar amount of each component in the reaction to prepare the protein assembly system. In one embodiment, the molar ratio of the first protein / antibody (e.g., anti-DNP) to streptavidin is about 1:3. In additional embodiments, the anti-DNP is labeled with an average of about or at least about 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, or 10 blue dyes or green dyes.In other embodiments, each streptavidin is labeled with an average of about or at least about 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5 or 10 green dyes or blue dyes. In other embodiments, the remaining biotin binding sites of the streptavidin in the dual protein assembly system are blocked with a molecule containing a biotin moiety or an analog thereof, so that the dual protein assembly system can only specifically bind to nucleotides containing a DNP moiety.

[0175] One aspect of the present disclosure relates to a nucleotide complex comprising a protein assembly system as described herein. In some embodiments, the nucleotide is conjugated to the protein assembly system via non-covalent interactions. In yet another embodiment, the protein assembly system is bound to a hapten portion of the nucleotide, and the hapten portion of the nucleotide is capable of specifically binding to at least one protein in the protein of the protein assembly system. In yet further embodiments, the hapten portion of the nucleotide comprises a DIG portion or a DNP portion. In yet another embodiment, the hapten portion of the nucleotide is covalently linked to a nucleobase via a cleavable linker.

[0176] Another aspect of the present disclosure relates to oligonucleotides or polynucleotides comprising nucleotide complexes as described herein. In yet another embodiment, the oligonucleotides or polynucleotides are at least partially complementary and hybridized to a target polynucleotide fixed on the surface of a solid support. In yet another embodiment, the solid support comprises a plurality of different fixed target polynucleotides, wherein the density of the fixed target polynucleotides (i.e., clusters) on the solid support is about or at least about 50,000 / mm 2 、100,000 / mm 2 、150,000 / mm 2 、200,000 / mm 2 、250,000 / mm 2 、300,000 / mm 2 、350,000 / mm 2 or 400,000 / mm 2 .

[0177] B. Labeled avidin

[0178] Some aspects of the present disclosure relate to a labeled avidin for use as an affinity reagent as described herein or as a part of a protein assembly system as described herein. Specifically, the labeled avidin can be a multi-dye labeled streptavidin or neutravidin, wherein at least one biotin binding site of the avidin is capped by a molecule containing a biotin moiety or an analog thereof, and wherein the labeled avidin comprises at least one (or only one) open biotin binding site (i.e., for binding to a nucleotide containing the biotin moiety or a linker containing the biotin moiety of the protein assembly system).

[0179] In some embodiments of the labeled avidin (e.g., streptavidin or neutravidin) described herein, one to three biotin binding sites of the avidin are blocked by the molecule containing the biotin moiety or its analog. In some embodiments, one biotin binding site of the avidin is blocked by the molecule containing the biotin moiety or its analog. In some embodiments, two biotin binding sites of the avidin are blocked by the molecule containing the biotin moiety or its analog. In some embodiments, three biotin binding sites of the avidin are blocked by the molecule containing the biotin moiety or its analog. In some embodiments, the molecule containing the biotin moiety or its analog is a free molecule that is not covalently attached to a nucleotide or nucleoside. For example, a molecule containing a biotin moiety or its analog may contain free biotin. Biotin-TEG, bibiotin, PC biotin, desthiobiotin-TEG, biotin azide, or a combination thereof. In other embodiments, the molecule containing the biotin moiety or its analogue comprises a biotin moiety covalently attached to a nucleotide or nucleoside, optionally connected via a linker (e.g., a cleavable linker). In some embodiments of the avidin of the labeling described herein, the avidin is labeled with two to eight fluorescent dye moieties. In some embodiments, the avidin is labeled with two fluorescent dye moieties. In some embodiments, the avidin is labeled with five to seven fluorescent dye moieties.

[0180] In some embodiments of the labeled avidin described herein, the fluorescent dye moieties are identical and / or spectrally indistinguishable. In some embodiments, the fluorescent dye moieties of the avidin can be excited by a light source with a wavelength between about 400 nm and about 650 nm. For example, the light source can have a wavelength of about 400 nm, 410 nm, 420 nm, 430 nm, 440 nm, 445 nm, 450 nm, 455 nm, 460 nm, 465 nm, 470 nm, 480 nm, 490 nm, 500 nm, 510 nm, 515 nm, 520 nm, 525 nm, 530 nm, 535 nm, 540 nm, 545 nm, 550 nm, 560 nm, 570 nm, 580 nm, 590 nm, 600 nm, 610 nm, 620 nm, 630 nm, 640 nm, or 650 nm, or a range defined by any two of the foregoing values. For example, the wavelength is in any of the following ranges: about 440-470nm, about 450-460nm, about 510-545nm, 515-540nm, 520-535nm, or 525-535nm. In some additional embodiments, the fluorescent dye portion can be excited by a light source having a wavelength between about 450nm and about 460nm, or between about 520nm and about 535nm.

[0181] Further details regarding labeled avidin can be found in U.S. Application No. 18 / 190,330, which is incorporated herein by reference.

[0182] C. Depolymerizable Labeled Nanoparticles

[0183] Another aspect of the present disclosure relates to a labeled nanoparticle, the labeled nanoparticle comprising:

[0184] A polymer matrix comprising a plurality of detectable labels, wherein the backbone of the polymer comprises one or more cleavable moieties, and wherein the labeled nanoparticles are capable of being degraded into smaller polymeric chains upon cleavage of the cleavable moieties.

[0185] In some embodiments of the labeled nanoparticles described herein, the plurality of detectable labels comprise or are fluorophores capable of being excited by a light source having a wavelength between about 400 nm to about 650 nm, about 420 nm to about 600 nm, or about 450 nm to about 550 nm.

[0186] In some embodiments of the labeled nanoparticles described herein, the plurality of detectable labels are fluorophores capable of being excited by a light source having a wavelength between about 450 nm and about 460 nm.

[0187] In some embodiments of the labeled nanoparticles described herein, the smaller polymeric chains of the degraded nanoparticles are water soluble.

[0188] In some embodiments of the labeled nanoparticles described herein, the cleavable moiety is chemically degradable, enzymatically degradable, thermally degradable, or photodegradable.

[0189] In some embodiments of the labeled nanoparticles described herein, the cleavable moiety comprises a disulfide, an azide, or an allylic moiety, or a combination thereof.

[0190] In some embodiments of the labeled nanoparticles described herein, the polymer comprises a cross-linked or dendritic polymer or a liposome.

[0191] In some embodiments of the labeled nanoparticles described herein, the polymer comprises polyacrylamide, polyglycolic acid (PGA), polyvinyl alcohol (PVA).

[0192] In some embodiments of the labeled nanoparticles described herein, the plurality of detectable labels are covalently attached to the polymer matrix.

[0193] In some embodiments of the labeled nanoparticles described herein, the plurality of detectable labels are encapsulated or physically confined within the polymer matrix.

[0194] In some embodiments of the labeled nanoparticles described herein, the labeled nanoparticles further comprise one or more proteins attached thereto.

[0195] As the pore density of the patterned flow cell used in SBS increases, the size of the pores decreases. This leaves less area for the template strand. Since the previous FFN has been conjugated with one fluorophore per base, the fluorescence signal per pore also decreases.

[0196] As discussed herein, it is possible that FFN is conjugated to a hapten, and flow into a corresponding hapten binding partner with one or more fluorophores incorporated. In some embodiments, the binding partner itself is conjugated to a nanoparticle or quantum dot, and one or more fluorophores incorporated are conjugated to the nanoparticle or quantum dot. However, these nanoparticles may still be adsorbed on the DNA clusters of the flow cell, even after the washing step, producing high background fluorescence. The depolymerizable nanoparticles can be washed more easily from the DNA clusters.

[0197] Figure 2A The non-depolymerizable nanoparticles are schematically shown, while Figure 2BSchematically illustrates exemplary depolymerizable fluorescent nanoparticles according to the present embodiment. Each nanoparticle may include a polymer matrix. In addition, the nanoparticle may include a ligand binding protein (i.e., a hapten binding partner) via which the nanoparticle may bind to one or more dye-labeled molecules. In alternative embodiments, the dye label may be covalently attached to the nanoparticle. Unlike conventional nanoparticles, the polymer matrix of the depolymerizable fluorescent nanoparticle may include a cleavable portion. Figure 2B In the example shown, the cleavable moiety may be a disulfide bond. If a suitable cleavage mixture is introduced to the depolymerizable fluorescent nanoparticles during SBS, the nanoparticles may be broken down into small soluble chains that may be washed away.

[0198] although Figure 2B Nanoparticles comprising disulfide bonds are depicted, but other cleavable bonds may be used in depolymerizable nanoparticles. In some embodiments, disulfide bonds may be cleaved by a reducing agent. In some embodiments, the allylic bond may be cleaved by a Pd(0) complex (e.g., tris(3,3',3"-phosphinotri(benzenesulfonate)palladium(0) nonasodium salt nonahydrate), or the same palladium cleavage reagent described herein for cleaving the 3' capping group / cleavable linker. In some embodiments, the azidomethyl bond may be cleaved by tris(2-carboxyethyl)phosphine (TCEP) or tris(hydroxypropyl)phosphine (THP or THPP). In some embodiments, the diol bond may be cleaved by NaIO4. In some embodiments, the polyglycolic acid bond may be cleaved by H2O or an enzyme having esterase activity. In some embodiments, Polyvinyl alcohol (PVA) bonds can be cleaved by heating, enzymatic action or oxidation. In some embodiments, ester bonds can be cleaved by hydrolysis, heating or alkaline conditions. In some embodiments, photocleavable bonds can be cleaved by exposure to UV light. In some embodiments, nanoparticles may include polymer vesicles. Polymer vesicles may be degraded by surfactants and / or hydrolysis at a specific pH range. In some embodiments, nanoparticles may include liposomes. Liposomes may be degraded by surfactants, specific temperature ranges and / or by hydrolysis at a specific pH range. Other suitable cleavable bonds may be used.

[0199] Fluorescent dyes

[0200] Various fluorescent dyes can be used as detectable labels of affinity reagents described herein in the present disclosure, particularly those dyes that can be excited by blue light or green light. These dyes can also be referred to as "blue dyes" and "green dyes", respectively. Examples of various types of blue dyes, including but not limited to coumarin dyes, chromoquinoline dyes, naphthylimide dyes, and diboron heterocyclic compounds, are disclosed in U.S. Patent Publication Nos. 2018 / 0094140, 2018 / 0201981, 2020 / 0277529, 2020 / 0277670, 2021 / 0188832, and 2022 / 0033900, and U.S. Serial Nos. 17 / 550271, 17 / 736688, 18 / 190531, 63 / 356412, and 63 / 492896, each of which is incorporated by reference in its entirety. Non-limiting examples of blue dyes include:

[0201] (Coumarin dye A), (Coumarin dye C) and (Coumarin dye D), and salts, liquid crystal forms and optionally substituted analogs thereof. For example, analogs having -SO3H substitution on the alkyl group.

[0202] Examples of green dyes include cyanine or polymethine dyes disclosed in International Patent Publication Nos. WO2013 / 041117, WO2014 / 135221, WO2016 / 189287, WO2017 / 051201, and WO2018 / 060482A1, each of which is incorporated by reference in its entirety. Non-limiting examples of green dyes include:

[0203] (cyanine dye B), and salts, liquid crystal forms and optionally substituted analogs thereof.

[0204] In some embodiments, the fluorescent dyes described herein may be further modified to introduce one or more substituents (e.g., -S03H, -OH, -C(O)OH, -C(O)OR, wherein R is an unsubstituted or substituted C1-C6 alkyl) to increase the hydrophilicity of the dye when the dye is conjugated to the antibody / protein (i.e., hapten binding partner) described herein while maintaining the signal intensity of the dye. In some such embodiments, the first detectable label described in the kits and protein assembly systems of the present disclosure may be a coumarin dye having a structure of formula (I):

[0205]

[0206] Where m is an integer of 1, 2 or 3;

[0207] n is an integer of 1, 2, 3, 4 or 5;

[0208] R 1 is -C(O)OC1-C6 alkyl, -SO3H, -OH, optionally substituted 5- to 10-membered heteroaryl, optionally substituted 3- to 10-membered heterocyclyl, optionally substituted phenyl, or -OR x , where R x is an optionally substituted 5- to 10-membered heteroaryl, an optionally substituted 3- to 10-membered heterocyclyl, or an optionally substituted phenyl. In some embodiments, m is 1. In some embodiments, n is 1. In some other embodiments, n is 3. In further embodiments, m is 1 and n is 3. In one embodiment, R 1 Yes -C(O)O t In another embodiment, R 1 In another embodiment, R 1 is furanyl (eg, 2-furanyl). In another embodiment, R 1 yes Additional non-limiting embodiments of coumarin dyes include:

[0209]

[0210]

[0211] When the dye forms a covalent bond with an affinity reagent (e.g., avidin, protein, or antibody), the carboxyl group of the dye can react with the amino functional group of the affinity reagent to form an amide bond. For example, the dye of formula (I) comprises a moiety that is covalently bound to the affinity reagent.

[0212] 3' blocking group

[0213] The nucleotides described herein may also have a 3' capping group covalently attached to the deoxyribose of the nucleotide. Various 3' capping groups are disclosed in WO2002 / 029003, WO2004 / 018497 and WO2014 / 139596. For example, the capping group may be an azidomethyl group (-CH2N3) or a substituted azidomethyl group (e.g., -CH(CHF2)N3 or CH(CH2F)N3), or an allyl group, each attached to the 3' oxygen atom of the deoxyribose moiety. In some embodiments, the 3' capping group is an azidomethyl group, forming 3'-OCH2N3 with the 3' carbon of ribose or deoxyribose.

[0214] Additional 3' capping groups are disclosed in U.S. Publication No. 2020 / 0216891A1, which is incorporated by reference in its entirety. Non-limiting examples of acetal capping groups are (AOM),

[0215]

[0216] Each is covalently attached to the 3' carbon of deoxyribose.

[0217] Deprotection of 3' blocking group

[0218] In some embodiments, the 3' hydroxyl protecting group can be removed or deprotected by using a water-soluble phosphine reagent, such as an azidomethyl group to generate a free 3'-OH. Non-limiting examples include tris (hydroxymethyl) phosphine (THMP), tris (hydroxyethyl) phosphine (THEP) or tris (hydroxypropyl) phosphine (THP or THPP). The 3'-acetal end-capping group described herein can be removed or cracked under various chemical conditions. For 3' end-capping groups containing allyl moieties, non-limiting cracking conditions include Pd (II) complexes in the presence of phosphine ligands, such as tris (hydroxymethyl) phosphine (THMP) or tris (hydroxypropyl) phosphine (THP or THPP), such as Pd (OAc) 2 or allyl chloride Pd (II) dimers. For those end-capping groups containing alkynyl groups (e.g., ethynyl), it can also be removed by Pd (II) complexes (e.g., Pd (OAc) 2 or allyl chloride Pd (II) dimers) in the presence of phosphine ligands (e.g., THP or THMP).

[0219] Palladium cleavage reagent

[0220] In some other embodiments, 3'-capping groups such as allyl or AOM as described herein can be cleaved by a palladium catalyst. In some such embodiments, the Pd catalyst is water-soluble. In some such embodiments, it is a Pd(0) complex (e.g., tris(3,3',3"-phosphinyltri(benzenesulfonate)palladium(0) nonahydrate). In some cases, the Pd(0) complex can be generated in situ by reducing the Pd(II) complex with reagents such as olefins, alcohols, amines, phosphines, or metal hydrides. Suitable palladium sources include Na2PdCl4, Li2PdCl4, Pd(CH3CN)2Cl 2、(PdCl(C3H5))2, [Pd(C3H5)(THP)]Cl, [Pd(C3H5)(THP)2]Cl, Pd(OAc)2, Pd(Ph3)4, Pd(dba)2, Pd(Acac)2, PdCl2(COD), Pd(TFA)2, Na2PdBr4, K2PdBr4, PdCl2, PdBr2, and Pd(NO3)2. In one such embodiment, the Pd(0) complex is generated in situ from Na2PdCl4 or K2PdCl4. In another embodiment, the palladium source is allylpalladium(II) chloride dimer [(PdCl(C3H5))2]. In some embodiments, the Pd(0) complex is generated in aqueous solution by mixing the Pd(II) complex with a phosphine. Suitable phosphines include water-soluble phosphines such as tri(hydroxypropyl)phosphine (THP), tri(hydroxymethyl)phosphine (THMP), 1,3,5-triaza-7-phosphaadamantane (PTA), bis(p-sulfonatophenyl)phenylphosphine dihydrate potassium salt, tri(carboxyethyl)phosphine (TCEP) and triphenylphosphine-3,3',3"-trisulfonic acid trisodium salt.

[0221] In some embodiments, the palladium catalyst is prepared by mixing [(allyl)PdCl]2 with THP in situ. The molar ratio of [(allyl)PdCl]2 to THP can be about 1:1, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, 1:5.5, 1:6, 1:6.5, 1:7, 1:7.5, 1:8, 1:8.5, 1:9, 1:9.5, or 1:10. In one embodiment, the molar ratio of [(allyl)PdCl]2 to THP is 1:10. In some other embodiments, the palladium catalyst is prepared by mixing a water-soluble Pd reagent such as Na2PdCl4 or K2PdCl4 with THP in situ. The molar ratio of Na2PdCl4 or K2PdCl4 to THP can be about 1:1, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, 1:5.5, 1:6, 1:6.5, 1:7, 1:7.5, 1:8, 1:8.5, 1:9, 1:9.5, or 1:10. In one embodiment, the molar ratio of Na2PdCl4 or K2PdCl4 to THP is about 1:3. In another embodiment, Na2PdCl4 or K2PdCl4 can be about 1:1. K2The molar ratio of PdCl4 to THP is about 1:3.5. In another embodiment, the molar ratio of Na2PdCl4 or K2PdCl4 to THP is about 1:2.5. In some additional embodiments, one or more reducing agents may be added, such as ascorbic acid or a salt thereof (e.g., sodium ascorbate). In some embodiments, the cleavage mixture may contain additional buffer reagents, such as primary amines, secondary amines, tertiary amines, carbonates, phosphates, or borates, or combinations thereof. In some additional embodiments, the buffer reagents include ethanolamine (EA), tris(hydroxymethyl)aminomethane (Tris), glycine, sodium carbonate, sodium phosphate, sodium borate, 2-dimethylethanolamine (DMEA), 2-diethylethanolamine (DEEA), N,N,N',N'-tetramethylethylenediamine (TEMED) or N,N,N',N'-tetraethylethylenediamine (TEEDA) or 2-piperidineethanol (also known as (2-hydroxyethyl)piperidine, having the structure ), or a combination thereof. In one embodiment, the buffer reagent comprises DEEA, or is DEEA. In another embodiment, the buffer reagent comprises or is (2-hydroxyethyl)piperidine. In another embodiment, the buffer contains one or more inorganic salts, such as carbonate, phosphate or borate, or a combination thereof. In one embodiment, the inorganic salt is a sodium salt.

[0222] Cleavable linker

[0223] In some embodiments, the hapten moiety of nucleotides described herein is covalently attached to the core base of nucleotides via a cleavable joint. The use of the term "cleavable linking group" is not intended to imply the need to remove the entire linking group. The cleavage site can be located on the linking group to ensure that a part of the linking group remains connected to a certain position of dyestuff and / or substrate moiety after cleavage. In a non-limiting example, the cleavable linking group can be an electrophilic cleavable linking group, a nucleophilic cleavable linking group, a photocleavable linking group, cleavable under reducing conditions (for example, a linking group containing a disulfide or azide), cleavable under oxidizing conditions, by using a safe capture linking group cleavable, and cleavable by an elimination mechanism. Using a cleavable linking group to connect the dye compound to the substrate moiety ensures that if necessary, the label can be removed after detection, thereby avoiding any interfering signal in the downstream step.

[0224] Useful linker groups can be found in PCT Publication WO2004 / 018493 (incorporated herein by reference), examples of which include linkers that can be cleaved using water-soluble phosphines or water-soluble transition metal catalysts formed by transition metals and at least partially water-soluble ligands. In aqueous solutions, the latter form at least partially water-soluble transition metal complexes. Such cleavable linkers can be used to connect the bases of nucleotides to labels, such as dyes described herein.

[0225] Particular linking groups include those disclosed in PCT Publication WO 2004 / 018493 (incorporated herein by reference), such as those comprising a moiety of the formula:

[0226]

[0227] (wherein X is selected from the group consisting of O, S, NH and NQ, wherein Q is C 1-10 A substituted or unsubstituted alkyl group, Y is selected from the group consisting of O, S, NH and N (allyl), T is hydrogen or C1-C 10 substituted or unsubstituted alkyl group, and * indicates the position where the moiety is attached to the rest of the nucleotide or nucleoside). In some aspects, the linker connects the base of the nucleotide to a label, such as a dye compound described herein.

[0228] Additional examples of linkers include those disclosed in U.S. Publication No. 2016 / 0040225 (incorporated herein by reference), such as those comprising a moiety of the formula:

[0229]

[0230] (where * indicates the position where the moiety is attached to the rest of the nucleotide or nucleoside). The linker moieties presented herein may include all or part of the linker structure between the nucleotide / nucleoside and the label.

[0231] Other examples of connectors are disclosed in U.S. Patent Publication No. 2020 / 0216891A1, which is incorporated by reference in its entirety:

[0232]

[0233] Wherein B is a nucleobase; n is 1, 2, 3, 4, 5; k is 1; Z is -N3 (azido), -O-C1-C6 alkyl, -O-C2-C6 alkenyl or -O-C2-C6 alkynyl; and Hap comprises a hapten portion as described herein, and the dye portion may contain an additional linker structure. It is understood by those of ordinary skill in the art that the hapten portion as described herein is covalently bound to the linker by reacting a functional group (e.g., carboxyl) of the hapten compound with a functional group (e.g., amino) of the linker. In one embodiment, the cleavable linker comprises ("AOL" linker moiety), wherein Z is -O-allyl. For purposes of this disclosure, a nucleotide may contain multiple cleavable linker repeat units (eg, k is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10).

[0234] The hapten moiety can be attached to any position on the nucleotide base, for example, via a linker. In a particular embodiment, the resulting analog can still be subjected to Watson-Crick base pairing. Specific nucleobase labeling sites include the C5 position of a pyrimidine base or the C7 position of a 7-deazapurine base. As described above, a linker group can be used to covalently attach a dye to a nucleotide.

[0235] In certain embodiments, the unlabeled nucleotides may be enzymatically incorporable and enzymatically extendable. Thus, the linker moiety may have sufficient length to connect the nucleotide to the compound so that the compound does not significantly interfere with the overall binding and recognition of the nucleotide by the nucleic acid replicating enzyme. Thus, the linker may also include a spacer unit, such as one or more PEG units (-OCH2CH2-) n , wherein n is an integer from 1 to 20, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15. The spacer distance is, for example, the distance in nucleotide bases from the cleavage site or label.

[0236] The unlabeled nucleosides or nucleotides containing haptens described herein may have the following formula:

[0237]

[0238] wherein Hap is a hapten moiety as described herein; B is a nucleobase such as uracil, thymine, cytosine, adenine, 7-deazaadenine, guanine, 7-deazaguanine, etc.; L is an optional linker that may or may not be present; R' may be H, or -OR' is a monophosphate, a diphosphate, a triphosphate, a thiophosphate, a phosphate analog, -O- attached to a reactive phosphorus-containing group, or -O- protected by a blocking group; R" is H or OH; and R"' is H, a 3' hydroxyl blocking group as described herein, or -OR"' forms a phosphoramidite. wherein -OR"' is a phosphoramidite and R' is an acid-cleavable hydroxyl protecting group that allows subsequent monomer coupling under automated synthesis conditions. In some additional embodiments, B comprises or their optionally substituted derivatives and analogs. In some additional embodiments, the nucleobase comprises the structure

[0239] In another alternative embodiment, there is no capping group present on the 3' carbon of the pentose, and the labeled avidin attached to the base via a linker, for example, may have a size or structure sufficient to act as a barrier to the incorporation of additional nucleotides. Thus, the barrier may be due to steric hindrance or to a combination of size, charge, and structure, regardless of whether the dye is attached to the 3' position of the sugar.

[0240] The use of capping groups allows for control of polymerization, such as by stopping extension when an unlabeled nucleotide is incorporated. If the capping effect is reversible, e.g., by way of non-limiting example, extension can be stopped at certain points by changing the chemical conditions or by removing the chemical barrier and then allowed to continue.

[0241] In a specific embodiment, the linker (between the hapten moiety and the nucleotide) and the blocking group both exist and are separate parts. In a specific embodiment, the linker and the blocking group are all cleavable under identical or substantially similar conditions. Therefore, the deprotection and deblocking processes may be more effective because only a single treatment is needed to remove both the dye compound and the blocking group. However, in some embodiments, the linker and the blocking group do not need to be cleavable under similar conditions, but can be cleaved separately under different conditions.

[0242] Non-limiting exemplary unlabeled nucleotides as described herein include:

[0243]

[0244]

[0245] wherein L represents a linker, including a cleavable linker as described herein; R represents a ribose or deoxyribose moiety as described above, or a ribose or deoxyribose moiety having the 5' position substituted with a monophosphate, diphosphate or triphosphate; and Hap represents a hapten moiety as described herein.

[0246] In some embodiments, a non-limiting exemplary unlabeled nucleotide containing a hapten moiety covalently attached via a cleavable linker is as follows:

[0247]

[0248]

[0249]

[0250] wherein PG represents a 3′-capping group as described herein; p is an integer of 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10; and m is 0, 1, 2, 3, 4, or 5. In one embodiment, —O—PG is AOM. In another embodiment, —O—PG is —O—azidomethyl. In one embodiment, k is 5. In some additional embodiments, p is 1, 2, or 3; and m is 5. Refers to the point of attachment of the hapten moiety to the cleavable linker as a result of the reaction between the amino group of the linker moiety and the carboxyl group of the hapten. In further embodiments, the nucleotide may be attached to the hapten moiety via more than one identical cleavable linker (such as LN3-LN3, sPA-sPA, AOL-AOL). In other embodiments, the nucleotide may be attached to the hapten moiety via two or more different cleavable linkers (such as sPA-LN3, sPA-sPA-LN3, sPA-LN3-LN3, etc.). In any of the embodiments of the labeled nucleotides described herein, the nucleotide is a nucleotide triphosphate. In further embodiments, the nucleotide has a 2' deoxyribose sugar.

[0251] Sequencing methods

[0252] Additional aspects of the present disclosure relate to a method for determining the sequence of a plurality of different target polynucleotides in parallel, the method comprising:

[0253] (a) contacting a solid support with a solution containing a sequencing primer under hybridization conditions, wherein the solid support comprises a plurality of different target polynucleotides immobilized thereon; and the sequencing primer is complementary to at least a portion of the target polynucleotide;

[0254] (b) contacting the solid support with an aqueous solution comprising a DNA polymerase and one or more of four different types of unlabeled nucleotides (e.g., an incorporation mixture containing A, C, G, T, or U) under conditions suitable for DNA polymerase-mediated primer extension, and incorporating one type of nucleotide into the sequencing primer to produce an extended copy polynucleotide; wherein

[0255] Each of the four types of nucleotides comprises a 3' blocking group;

[0256] The first type of unlabeled nucleotides comprises a first hapten;

[0257] The second type of unlabeled nucleotides comprises a second hapten;

[0258] (c) contacting the extended copy polynucleotide with a set of affinity reagents under conditions where one of the affinity reagents specifically binds to the incorporated unlabeled nucleotide to provide a labeled extended copy polynucleotide;

[0259] (d) imaging the solid support and performing one or more fluorescence measurements of the extended copy polynucleotide; and

[0260] (e) removing the 3' blocking group of the incorporated nucleotide;

[0261] The affinity reagent comprises:

[0262] a first affinity reagent comprising a first hapten-binding partner capable of specifically binding to the first type of unlabeled nucleotides; and

[0263] a second affinity reagent comprising a second hapten binding partner capable of specifically binding to the second type of unlabeled nucleotides;

[0264] wherein the first affinity reagent comprises one or more first detectable labels, the one or more first detectable labels being capable of being excited by a first excitation light source, the second affinity reagent comprises one or more second detectable labels, the one or more second detectable labels being capable of being excited by a second excitation light source, and wherein the one or more first detectable labels are spectrally distinguishable from the one or more second detectable labels; and

[0265] wherein one of the first excitation light source and the second excitation light source has a wavelength of about 450 nm to about 460 nm, and the other of the first excitation light source and the second excitation light source has a wavelength of about 520 nm to about 540 nm;

[0266] In some embodiments of the sequencing methods described herein, the first hapten is covalently linked to the nucleobase of the first type of unlabeled nucleotide via a cleavable linker. In some additional embodiments, the second hapten is covalently linked to the nucleobase of the second type of unlabeled nucleotide via a cleavable linker.

[0267] Two-tag sequencing

[0268] In some embodiments of the sequencing methods described herein, the third type of unlabeled nucleotides comprises a mixture of the third type of unlabeled nucleotides containing the first hapten and the third type of unlabeled nucleotides containing the second hapten, and wherein the first affinity reagent and the second affinity reagent are both capable of specifically binding to the third type of unlabeled nucleotides. In some other embodiments, each of the first hapten and the second hapten is covalently linked to the nucleobase of the third type of nucleotides via a cleavable linker. In this case, the incorporation of the first type of nucleotides is determined by the signal state in the first fluorescence measurement and the dark state in the second fluorescence measurement. The incorporation of the second type of nucleotides is determined by the signal state in the first fluorescence measurement and the dark state in the second fluorescence measurement. The incorporation of the third type of nucleotides is determined by the signal state in the first fluorescence measurement and the signal state in the second fluorescence measurement. The incorporation of the fourth type of nucleotides is determined by the dark state in the first fluorescence measurement and the dark state in the second fluorescence measurement. The sequencing system described herein may also be referred to as a two-label system because there are two affinity reagents labeled with spectrally distinguishable detectable labels, respectively.

[0269] In some embodiments of the two-tag sequencing method described herein, the first hapten comprises a biotin moiety, and the first hapten binding partner comprises avidin. In yet another embodiment, the avidin is streptavidin. In yet another embodiment, the avidin is neutravidin. In other embodiments, one or more biotin binding sites of the avidin are capped by a molecule containing a biotin moiety or an analog thereof. In some embodiments, the second hapten comprises a DNP moiety, and the second hapten binding partner comprises an anti-DNP antibody. In some embodiments, the third type of unlabeled nucleotides comprises a mixture of a third type of unlabeled nucleotides containing a biotin moiety and a third type of unlabeled nucleotides containing a DNP moiety. In other embodiments, the second hapten comprises a DIG moiety, and the second hapten binding partner comprises an anti-DIG antibody. In other embodiments, the third type of unlabeled nucleotides comprises a mixture of a third type of unlabeled nucleotides containing a biotin moiety and a third type of unlabeled nucleotides containing a DIG moiety.

[0270] Triple-index sequencing

[0271] In some embodiments of the methods described herein, the third type of unlabeled nucleotides comprises a third hapten, and the set of affinity reagents further comprises a third affinity reagent, the third affinity reagent comprising a third hapten binding partner capable of specifically binding to the third hapten. In some such embodiments, the third hapten is covalently linked to the nucleobase of the third type of unlabeled nucleotides via a cleavable linker. In this case, the incorporation of the first type of nucleotides is determined by the signal state in the first fluorescence measurement and the dark state in the second fluorescence measurement. The incorporation of the second type of nucleotides is determined by the signal state in the first fluorescence measurement and the dark state in the second fluorescence measurement. The incorporation of the third type of nucleotides is determined by the signal state in the first fluorescence measurement and the signal state in the second fluorescence measurement. The incorporation of the fourth type of nucleotides is determined by the dark state in the first fluorescence measurement and the dark state in the second fluorescence measurement. The sequencing system described herein may also be referred to as a three-tag system because there are three affinity reagents labeled with spectrally distinguishable detectable labels, respectively.

[0272] In some embodiments of the three-tag sequencing method described herein, the first hapten comprises a biotin moiety, and the first hapten binding partner comprises avidin. In yet another embodiment, the avidin is streptavidin. In yet another embodiment, the avidin is neutravidin. In another embodiment, one or more biotin binding sites of the avidin are capped by a molecule containing a biotin moiety or an analog thereof. In some embodiments, one of the second hapten and the third hapten comprises a DNP moiety, and the other of the second hapten and the third hapten comprises a DIG moiety. For example, the second hapten comprises a DNP moiety, and the second hapten binding partner comprises an anti-DNP antibody. The third hapten comprises a DIG moiety, and the third hapten binding partner comprises an anti-DIG antibody.

[0273] In some other embodiments of the three-tag sequencing method described herein, one of the first hapten and the second hapten comprises a DNP portion, and the other of the first hapten and the second hapten comprises a DIG portion. For example, the first hapten comprises a DNP portion, and the first hapten binding partner comprises an anti-DNP antibody. The second hapten comprises a DIG portion, and the second hapten binding partner comprises an anti-DIG antibody. In some other embodiments, the third hapten comprises a biotin portion, and the third hapten binding partner comprises an avidin. In yet another embodiment, the avidin is streptavidin. In yet another embodiment, the avidin is a neutravidin. In some other embodiments, one or more biotin binding sites of the avidin are capped by a molecule containing a biotin portion or an analog thereof.

[0274] In some other embodiments of the three-tag sequencing method described herein, the third affinity reagent comprises one or more first detectable labels and one or more second detectable labels. For example, the third affinity reagent may comprise or be a protein assembly system described herein. In some embodiments, the protein assembly system used in the three-tag method includes:

[0275] a protein (e.g., an antibody) labeled with one or more first detectable labels;

[0276] one or more biotin moieties covalently attached to the protein; and

[0277] one or more biotin-binding proteins (e.g., an avidin protein, such as streptavidin or neutravidin) that bind to the one or more biotin moieties via non-covalent interactions;

[0278] Wherein the biotin-binding protein is labeled with one or more second detectable labels, and wherein the first detectable label is spectrally distinguishable from the second detectable label. In further embodiments, the remaining biotin binding sites of the biotin-binding protein (e.g., avidin, such as streptavidin or neutravidin) in the protein assembly system are further blocked by a molecule containing a biotin moiety or an analog thereof, such that the protein assembly system can specifically bind only to the hapten portion of the protein (e.g., antibody).

[0279] Although certain haptens and hapten binding partners have been discussed in connection with a two-tag sequencing protocol or a three-tag sequencing protocol, other haptens and hapten binding partners, such as those exemplified in Table 1, may also be used.

[0280] In any embodiment of the sequencing method described herein, the spiked mixture further comprises a fourth type of unlabeled nucleotides, wherein the fourth type of unlabeled nucleotides cannot specifically bind to any of the affinity reagents. In addition, the fourth type of unlabeled nucleotides cannot be excited by the first light source or the second light source.

[0281] When used in reference to an imaging event, the term "signal state" refers to the state of a polynucleotide that is incorporated with unlabeled nucleotides and subsequently conjugated with a labeled affinity reagent as described herein, wherein a specific emission signal is generated by such an imaging event and the emission signal is measured, detected, or collected. For example, one or more detectable labels of an affinity reagent that specifically binds to the incorporated unlabeled nucleotides can be excited by a light source (e.g., a laser) of a specific wavelength and emit a fluorescent signal that is collected or detected in a single emission detection channel / filter, indicating a "signal state" in such an imaging event or fluorescence measurement.

[0282] The term "dark state" when referring to an imaging event refers to the state of a polynucleotide incorporating unlabeled nucleotides and subsequently conjugated to a labeled affinity reagent as described herein, wherein such imaging event does not produce a specific emission signal, or the emission signal is not measured, collected and / or detected.

[0283] In one example of the methods described herein, a "C" nucleotide complex is determined by a signal state in a first fluorescence measurement and a dark state in a second fluorescence measurement; a "T" nucleotide complex is determined by a signal state in a first fluorescence measurement and a signal state in a second fluorescence measurement; an "A" nucleotide complex is determined by a signal state in a first fluorescence measurement and a signal state in a second fluorescence measurement; and a "G" nucleotide complex is determined by a dark state in a first fluorescence measurement and a dark state in a second fluorescence measurement. In another example, a "T" nucleotide complex is determined by a signal state in a first fluorescence measurement and a dark state in a second fluorescence measurement; a "C" nucleotide complex is determined by a dark state in a first fluorescence measurement and a signal state in a second fluorescence measurement; an "A" nucleotide complex is determined by a signal state in a first fluorescence measurement and a signal state in a second fluorescence measurement; and a "G" nucleotide complex is determined by a dark state in a first fluorescence measurement and a dark state in a second fluorescence measurement.

[0284] In some embodiments of the sequencing methods described herein, step (e) also removes the detectable label of the incorporated nucleotide. In some such embodiments, the detectable label and 3' blocking group are removed in a single step (e.g., under the same chemical reaction conditions). In other embodiments, the detectable label and 3' blocking group are removed in two separate steps (e.g., the detectable label and 3' blocking group are removed under two separate chemical reaction conditions). In some embodiments, the detectable label is removed by the cleavage cleavable linker, wherein the hapten portion is covalently attached to the nucleotide. In some additional embodiments, the method further comprises (f) washing the solid support with an aqueous washing solution.

[0285] In some embodiments, the imaging step (d) is performed by two light sources (e.g., lasers) operating at different wavelengths. Specifically, one light source may have a wavelength between about 450 nm and about 460 nm, and the other light source may have a wavelength between about 510 nm and about 540 nm or between about 520 nm and about 535 nm. Thus, step (d) includes two separate imaging events and two fluorescence measurements.

[0286] In other embodiments of the sequencing methods described herein, steps (b) to (f) are performed in repeated cycles (e.g., at least 30, 50, 100, 150, 200, 250, 300, 400, or 500 times), and the method further comprises sequentially determining the sequence of at least a portion of the target polynucleotide based on the identity of each successively incorporated nucleotide complex. In some such embodiments, steps (b) to (f) are repeated for at least 50 cycles.

[0287] In some embodiments of the methods described herein, incorporation of the nucleotide complex is performed by a mutant of a 9N polymerase, such as those disclosed in WO 2005 / 024010, U.S. Patent Publication Nos. 2020 / 0131484A1, 2020 / 0181587A1, and U.S. Serial Nos. 63 / 412,241 and 63 / 433,971, each of which is incorporated by reference in its entirety. Exemplary polymerases include, but are not limited to, Pol 812, Pol 1901, Pol 1558, or Pol 963. The amino acid sequences of Pol 812, Pol 1901, Pol 1558, or Pol 963 DNA polymerases are described, for example, in U.S. Patent Publication Nos. 2020 / 0131484A1 and 2020 / 0181587A1.

[0288] In some embodiments of the methods described herein, the one or more four different types of nucleotides incorporated into the mixture in step (b) include nucleotide types selected from the group consisting of A, C, G, T, and U and their non-natural nucleotide analogs. In other embodiments, the incorporated mixture comprises four different types of nucleotide complexes (A, C, G, and T or U) or their non-natural nucleotide analogs. In other embodiments, the four different types of nucleotide conjugates are dATP, dCTP, dGTP, and dTTP or dUTP or their non-natural nucleotide analogs. In other embodiments, each type of nucleotide complex in the four types of nucleotide complexes incorporated into the mixture contains a 3' blocking group.

[0289] In any of the embodiments of the methods described herein, the density of the immobilized distinct target polynucleotides (i.e., clusters) on the solid support is about or at least about 50,000 / mm 2 、100,000 / mm 2 、150,000 / mm 2 、200,000 / mm 2 、250,000 / mm 2 、300,000 / mm 2 、350,000 / mm 2 or 400,000 / mm 2 .

[0290] Although certain haptens and hapten binding partners have been discussed in connection with a two-tag sequencing scheme, other haptens and hapten binding partners may also be used. Table 1 lists non-limiting examples of haptens and hapten binding partners. In additional embodiments, the spiked mixture used in the sequencing method may also include one or more labeled nucleotides. For example, the labeled nucleotides may contain a fluorescent label that cannot be excited by the first light source or the second light source.

[0291] In any of the embodiments of the methods described herein, the first detectable label may be a blue dye described herein (e.g., a coumarin dye of formula (I), (I-1), (I-2), (I-3), or (I-4)). In some additional embodiments, the second detectable label may be a green dye described herein (e.g., a cyanine dye).

[0292] In any embodiment of the sequencing method described herein, the method can reduce or eliminate sequence environment effect or sequence specific effect. Two-channel base detection depends on the ability to distinguish bases by the intensity in two emission color channels. This intensity modulation adds noise to the system, and when the sequence-specific intensity modulation shifts the intensity of a given cluster toward the decision boundary, it can cause false detection. Use a single ffN (such as ffA), then conjugate with a protein labeled with two colored dyes, the two colored dyes can produce color in two channels, thereby reducing or eliminating the sequence-specific intensity shift, and thereby improving base detection accuracy.

[0293] General description of sequencing by synthesis

[0294] In a particular embodiment, a synthesis step is performed and the synthesis step may optionally include incubating the template polynucleotide chain or the target polynucleotide chain with a reaction mixture comprising fluorescently labeled nucleotides of the present disclosure. A polymerase may also be provided under conditions that allow the formation of a phosphodiester bond between a free 3' hydroxyl group on the polynucleotide chain annealed to the template or target polynucleotide chain and a 5' phosphate group on the labeled nucleotide. Thus, the synthesis step may include directing the formation of a polynucleotide chain by complementary base pairing of nucleotides with the template / target chain.

[0295] In all embodiments of the method, the detection step can be performed when the polynucleotide chain into which the nucleotides of the mark are incorporated is annealed to the template / target chain, or after a denaturation step in which the two chains are separated. Additional steps, such as a chemical reaction step or an enzymatic reaction step, or a purification step may be included between the synthesis step and the detection step. Specifically, the polynucleotide chain into which the nucleotides of the mark are incorporated can be separated or purified, and then further processed or used for subsequent analysis. By way of example, the polynucleotide chain into which the labeled nucleotides as described herein are incorporated in the synthesis step can be used as a labeled probe or primer subsequently. In other embodiments, the product of the synthesis step shown herein can be subjected to further reaction steps, and if desired, the products of these subsequent steps are purified or separated.

[0296] Suitable conditions for the synthesis step will be well known to those familiar with standard molecular biology techniques. In one embodiment, the synthesis step can be similar to a standard primer extension reaction, which uses nucleotide precursors (including the nucleotides of labels as described herein) to form a polynucleotide chain (primer polynucleotide chain) complementary to the template / target chain in the presence of a suitable polymerase. In other embodiments, the synthesis step itself can form a part of the amplification reaction of the double-stranded amplification product of the mark, and the double-stranded amplification product of the mark is composed of the annealing complementary chain derived from the replication of the primer polynucleotide chain and the template polynucleotide chain. Other exemplary synthesis steps include nick translation, strand displacement polymerization, random DNA labeling, etc. The particularly useful polymerase for the synthesis step is a polymerase that can catalyze the incorporation of the nucleotides of the labels shown in this article. A variety of naturally occurring or mutated / modified polymerases can be used. By way of example, a thermostable polymerase can be used for the synthesis reaction performed using thermal cycling conditions, and a thermostable polymerase may not be desired by an isothermal primer extension reaction. Suitable thermostable polymerases capable of incorporating labeled nucleotides according to the present disclosure include those described in WO 2005 / 024010 or WO06120433, each of which is incorporated herein by reference. In synthesis reactions conducted at lower temperatures such as 37° C., the polymerase need not be a thermostable polymerase, and thus the choice of polymerase will depend on many factors, such as reaction temperature, pH, strand displacement activity, etc.

[0297] In specific non-limiting embodiments, the present disclosure encompasses methods of nucleic acid sequencing, resequencing, whole genome sequencing, single nucleotide polymorphism scoring, and any other application involving the detection of modified nucleotides or nucleosides labeled with the dyes set forth herein when incorporated into polynucleotides.

[0298] SBS generally involves the use of a polymerase or ligase to sequentially add one or more nucleotides or oligonucleotides to a growing polynucleotide chain in a 5' to 3' direction to form an extended polynucleotide chain complementary to the template / target nucleic acid to be sequenced. The identity of the bases present in the one or more added nucleotides can be determined in a detection or "imaging" step. The identity of the added bases can be determined after each nucleotide incorporation step. Conventional Watson-Crick base pairing rules can then be used to infer the sequence of the template. Using nucleotides labeled with dyes shown herein to determine the identity of a single base may be useful, for example, in the scoring of a single nucleotide polymorphism, and such single base extension reactions are within the scope of the present disclosure.

[0299] In one embodiment of the present disclosure, the sequence of the template / target polynucleotide is determined by detecting the incorporation of one or more nucleotides into a nascent chain complementary to the template polynucleotide to be sequenced by detecting a fluorescent label attached to the incorporated nucleotide. The sequencing of the template polynucleotide can be initiated with a suitable primer (or prepared as a hairpin construct, which will include a primer as part of the hairpin), and the nascent chain is extended in a one-by-one manner by adding nucleotides to the 3' end of the primer in a polymerase-catalyzed reaction.

[0300] In a specific embodiment, each of the different nucleotide triphosphates (A, T, G and C) can be labeled with a unique fluorophore, and a blocking group is also included at the 3' position to prevent uncontrolled polymerization. Alternatively, one of the four nucleotides can be unlabeled (dark). Polymerase incorporates nucleotides into a nascent chain complementary to the template polynucleotide / target polynucleotide, and the blocking group prevents further incorporation of nucleotides. Any unincorporated nucleotides can be washed out, and the fluorescent signal from the nucleotides of each incorporation can be optically "read" by a suitable device (such as a charge coupled device using a light source to excite and a suitable emission filter). Then (deprotection) 3' blocking groups and fluorescent dye compounds can be removed (simultaneously or sequentially) to expose the nascent chain for further incorporation of nucleotides.

[0301] As illustrated above, the method utilizes the presence of DNA polymerase to incorporate fluorescently labeled 3' blocked nucleotides A, G, C and T into a growing chain complementary to a fixed polynucleotide. Polymerase incorporates bases complementary to the target polynucleotide, but is prevented from further addition by 3' blocking groups. The label of the nucleotides incorporated can then be determined, and the blocking group is removed by chemical cleavage to allow further polymerization to occur. The nucleic acid template to be sequenced in the SBS reaction can be any polynucleotide desired to be sequenced. The nucleic acid template for sequencing reaction will generally include a double-stranded region with a free 3' hydroxyl group, which serves as a primer or starting point for adding additional nucleotides in the sequencing reaction. The region of the template to be sequenced will dangle the free 3' hydroxyl group on the complementary chain. The dangling region of the template to be sequenced can be single-stranded, but can also be double-stranded, provided that there is a "nick" on the chain complementary to the template chain to be sequenced, to provide a free 3' OH group for initiating a sequencing reaction. In such embodiments, sequencing can be performed by strand displacement. In certain embodiments, primers with free 3' hydroxyl groups can be added as separate components (e.g., short oligonucleotides) hybridized with the single-stranded region of the template to be sequenced. Alternatively, primers to be sequenced and template strands can each form a part of a partial self-complementary nucleic acid chain that can form an intramolecular duplex (such as a hairpin loop structure). Hairpin polynucleotides and methods that can be connected to a solid support are disclosed in PCT Publication No. WO0157248 and WO2005 / 047301, each of which is incorporated herein by reference. Nucleotide can be continuously added to the growth primer, resulting in a polynucleotide chain synthesized in the 5' to 3' direction. The properties of the bases added can be determined, particularly but not necessarily after each addition of nucleotides, thereby providing the sequence information of nucleic acid templates. Therefore, the mode of nucleotides being incorporated into nucleic acid chains (or polynucleotides) is to join the nucleotides to the free 3' hydroxyl groups of nucleic acid chains via forming a phosphodiester bond with the 5' phosphate group of the nucleotides.

[0302] The nucleic acid template to be sequenced can be DNA or RNA, or even a hybrid molecule composed of deoxynucleotides and ribonucleotides. The nucleic acid template can contain naturally occurring and / or non-naturally occurring nucleotides and natural or non-natural backbone bonds, provided that these do not prevent replication of the template in the sequencing reaction.

[0303] In certain embodiments, the nucleic acid template to be sequenced can be connected to a solid support via any suitable connection method known in the art (e.g., via covalent attachment). In certain embodiments, the template polynucleotide can be directly attached to a solid support (e.g., a silica-based support). However, in other embodiments of the present disclosure, the surface of the solid support can be modified in some way to allow direct covalent attachment of the template polynucleotide, or the template polynucleotide can be fixed by a hydrogel or polyelectrolyte multilayer that can itself be non-covalently attached to the solid support.

[0304] In some embodiments, the polynucleotides are directly connected to a carrier (e.g., a silica-based carrier, such as those disclosed in WO00 / 06770 (incorporated herein by reference)), wherein the polynucleotides are fixed to a glass carrier by reaction between an epoxy side group on the glass and an internal amino group on the polynucleotides. In addition, polynucleotides can be connected to a solid carrier by reaction of a sulfonyl nucleophilic substance with a solid carrier, for example, as described in WO2005 / 047301 (incorporated herein by reference). Other additional examples of solid-supported template polynucleotides are template polynucleotides connected to a hydrogel loaded on silica or other solid carriers, for example, as described in WO00 / 31148, WO01 / 01143, WO02 / 12566, WO03 / 014392, U.S. Patent No. 6,465,178 and WO00 / 53812, each of which is incorporated herein by reference.

[0305] The specific surface on which the template polynucleotide can be fixed is a polyacrylamide hydrogel. Polyacrylamide hydrogels are described in the references cited above and WO2005 / 065814, which is incorporated herein by reference. Specific hydrogels that can be used include those described in WO2005 / 065814 and U.S. Publication 2014 / 0079923. In one embodiment, the hydrogel is PAZAM (poly (N- (5-azidoacetamidopentyl) acrylamide-co-acrylamide)).

[0306] The DNA template molecule can be attached to a bead or microparticle, for example, as described in U.S. Pat. No. 6,172,218 (incorporated herein by reference). The attachment to a bead or microparticle can be used for sequencing applications. A bead library can be prepared, wherein each bead contains a different DNA sequence. Exemplary libraries and methods for their generation are described in Nature, 437, 376-380 (2005); Science, 309, 5741, 1728-1732 (2005), each of which is incorporated herein by reference. It is within the scope of the present disclosure to sequence an array of such beads using the nucleotides set forth herein.

[0307] The template to be sequenced can form part of an "array" on a solid support, in which case the array can take any convenient form. Therefore, the method of the present disclosure is applicable to all types of high-density arrays, including single-molecule arrays, clustered arrays, and bead arrays. Nucleotides labeled with dye compounds of the present disclosure can be used to sequence templates on substantially any type of array (including but not limited to those formed by fixing nucleic acid molecules on a solid support).

[0308] However, nucleotides labeled with dye compounds of the present disclosure are particularly advantageous in the context of sequencing clustered arrays. In clustered arrays, different regions on the array (commonly referred to as sites or features) include multiple polynucleotide template molecules. Generally speaking, the multiple polynucleotide molecules can not be distinguished individually by optical means, but are detected as a whole. Depending on the formation mode of the array, each site on the array can include multiple copies of a single polynucleotide molecule (for example, the site is homogeneous for specific single-stranded nucleic acid species or double-stranded nucleic acid species) or even a small amount of multiple copies of different polynucleotide molecules (for example, multiple copies of two different nucleic acid species). The clustered array of nucleic acid molecules can be produced using technology known in the art. By way of example, WO 98 / 44151 and WO00 / 18957 (each of these patents is incorporated herein by reference) describe a method for amplifying nucleic acids, wherein template and amplification product are both kept fixed on a solid support, so as to form an array consisting of a cluster or " colony" of fixed nucleic acid molecules. Nucleic acid molecules present on clustered arrays prepared according to these methods are suitable templates for sequencing using nucleotides labeled with the dye compounds of the present disclosure.

[0309] Nucleotides labeled with dye compounds of the present disclosure can also be used to sequence the templates on single molecule arrays. As used herein, the term "single molecule array" or "SMA" refers to a group of polynucleotide molecules distributed (or arranged) on a solid support, wherein the spacing between any single polynucleotide and all other polynucleotide molecules of the group makes it possible to distinguish the single polynucleotide molecules individually. Therefore, in some embodiments, the target nucleic acid molecules fixed to the surface of the solid support can be distinguished by optical means. This means that one or more different signals (each signal represents a polynucleotide) will appear in the distinguishable region of the specific imaging device used.

[0310] Single molecule detection can be achieved, wherein the spacing between adjacent polynucleotide molecules on the array is at least 100 nm, more specifically at least 250 nm, more specifically at least 300 nm, and even more specifically at least 350 nm. Therefore, each molecule can be individually resolved and detected as a single molecule fluorescent spot, and the fluorescence from the single molecule fluorescent spot also exhibits single-step photobleaching.

[0311] The terms "individually resolved" and "individually resolved" are used herein to specify that, when visualized, it is possible to distinguish a molecule on an array from its adjacent molecules. The spacing between the individual molecules on the array will be determined in part by the specific techniques used to resolve the individual molecules. The general characteristics of single molecule arrays will be understood by reference to published applications WO 00 / 06770 and WO 01 / 57248, each of which is incorporated herein by reference. Although one use of the labeled nucleotides of the present disclosure is for use in synthetic sequencing reactions, the effectiveness of such nucleotides is not limited to such methods. In fact, the labeled nucleotides described herein can be advantageously used in any sequencing method that requires detection of fluorescent labels attached to nucleotides incorporated into polynucleotides.

[0312] Specifically, nucleotides labeled with dye compounds of the present disclosure can be used in automated fluorescent sequencing protocols, especially fluorescent dye-terminator cycle sequencing based on the chain termination sequencing method of Sanger and colleagues. Such methods typically use enzymes and cycle sequencing to incorporate fluorescently labeled dideoxynucleotides into primer extension sequencing reactions. The so-called Sanger sequencing method and related protocols (Sanger-type) utilize randomized chain termination of labeled dideoxynucleotides.

[0313] Example

[0314] Additional embodiments are disclosed in more detail in the following examples, which are not intended to limit the scope of the claims in any way.

[0315] General procedure for determining protein labeling degree

[0316] The protein labeling degree of a dye can be estimated via absorbance measurements. First, if present, non-conjugated dye must be removed from a sample comprising a dye-labeled protein. In order to accurately determine the protein: dye ratio, the non-conjugated dye should be completely or substantially removed from the sample. For example, the dye can be removed by dialysis or gel filtration.

[0317] After removal of unconjugated dye, the absorbance of the protein:dye complex can be measured at 280 nm. 280 . The absorbance at 280 nm can be measured using a spectrophotometer. 280 The cuvette of the spectrophotometer may have a path length of 1 cm. If the initial absorbance measurement exceeds 2.0, the sample may be diluted by a dilution factor DF to reduce the absorbance to below 2.0 before re-measuring. Alternatively, the absorbance of the protein:dye complex, A max Available at wavelength λ max The dye has a maximum absorbance at this wavelength.

[0318] The molar concentration of protein in the sample can be calculated as follows:

[0319]

[0320] Where ε is the protein molar extinction coefficient, and CF is the correction factor used to adjust the dye's absorbance at 280 nm. The protein molar concentration can be used to calculate the protein:dye molar ratio:

[0321]

[0322] where ε' is the molar extinction coefficient of the fluorescent dye.

[0323] Example 1. Preparation of blue dye and green dye labeled streptavidin

[0324] To prepare blue dye-labeled streptavidin, 1 equivalent of coumarin dye A-PEG 12 -COOH was co-evaporated with 1 mL of DMF and dried under vacuum. Then, 10 equivalents of N,N-diisopropylethylamine and 1.1 equivalents of TSTU were added. The reaction was stirred at room temperature for 30 minutes to form coumarin dye A-PEG 12 -COOH activated ester. Then 10 μL of the activated ester was added to 1.0 mL of 2.0 mg / mL streptavidin (SA) in pH 6.5 potassium phosphate buffer. The resulting solution was stirred at room temperature for 1 hour, and the reaction mixture was purified by PD minitrap G-25 size exclusion column using pH 6.5, 10 mM potassium phosphate buffer to obtain the resulting streptavidin (coumarin A-PEG 12 ) complex. Coumarin dye A was covalently linked to streptavidin by reacting the activated ester of the carboxyl group with a lysine residue of streptavidin to form an amide bond. The amount of coumarin dye A covalently linked to streptavidin was calculated based on the general procedure for determining the degree of protein labeling by comparing the ratio of the absorbance wavelengths of the protein and the dye. The resulting protein-dye complex was identified as SA (Coumarin dye A-PEG12) 4.5 .

[0325] To prepare green dye-labeled streptavidin, 1 equivalent of cyanine dye B was co-evaporated with 1 mL of DMF and dried under vacuum. Then 10 equivalents of N,N-diisopropylethylamine and 1.1 equivalents of TSTU were added. The reaction was stirred at room temperature for 30 minutes to form the activated ester of cyanine dye B. The resulting 5.0 μM SA (coumarin dye PEG) in potassium phosphate at pH 6.5 was then added. 12 ) 4.5The complex was mixed with 10 μL of an activated ester of cyanine dye B and stirred at room temperature for 1 hour, and the reaction mixture was purified by a PD minitrap G-25 size exclusion column using a pH 8.0, 10 mM tris buffer to obtain a dual-labeled streptavidin (labeled with blue coumarin dye A and green cyanine dye B). The cyanine dye B labeling degree was based on the same as described above as SA (coumarin dye A-PEG 12 ) 4.5 (Cyanine Dye B) 1.4 The same general procedure was used for calculations. The complexes were characterized by nanodrop spectroscopy.

[0326] Coumarin dye A is disclosed in U.S. Patent Publication No. 2022 / 0033900A1, which, when conjugated to a protein (e.g., streptavidin) or an antibody (e.g., anti-DNP) via a PEG linker, has a structural moiety This coumarin dye can be excited by blue light of about 450 nm to about 460 nm (also referred to as a "blue dye"). Cyanine dye B is disclosed in International Patent Publication No. WO2014 / 135221A1 and, when conjugated to streptavidin, has a structural moiety This cyanine dye can be excited by green light from about 520 nm to about 540 nm (also referred to as a "green dye").

[0327] Example 2. Preparation of dual protein assembly system

[0328] First, 1 equivalent of coumarin dye A-PEG 12 -COOH was co-evaporated with 1 mL of DMF and dried under vacuum. Then 10 equivalents of N,N-diisopropylethylamine and 1.1 equivalents of TSTU were added. The reaction was stirred at room temperature for 30 minutes to form coumarin dye A-PEG 12 Then 20 μL of coumarin dye A-PEG 12 The activated ester of -COOH was added to 0.5 mL of 2.0 mg / mL (12.5 μM) anti-DNP antibody in pH 6.5 potassium phosphate buffer. The resulting solution was stirred at room temperature for 1 hour, and the reaction mixture was purified by PD minitrap G-25 size exclusion column using pH 6.5, 10 mM potassium phosphate buffer to obtain anti-DNP labeled with coumarin dye A. The dye labeling degree is based on the above-mentioned anti-DNP (coumarin dye A-PEG 12 )7. Then, 1 mL of 6.2 μM anti-DNP (coumarin dye A-PEG 12 )7 and 10 μL of 2.35 mg / mL NHS-PEG 12-biotin in DMA solution and stirred at room temperature for 1 hour, and the reaction mixture was purified by PD minitrap G-25 size exclusion column using pH 8.0, 10 mM tris buffer to obtain a solution concentration of 3.0 μM anti-DNP (coumarin dye A-peg 12 )7-Biotin.

[0329] The preparation of cyanine dye B-labeled streptavidin SA (cyanine dye B) 7 was similar to the procedure described in U.S. Patent Publication No. 2013 / 0079232A1, which is incorporated by reference in its entirety. The degree of dye labeling was calculated based on the general procedure described above for SA (cyanine dye B) 7. The 5-mercaptoethanol was then added to 20.5 μL of 10 mM tris buffer at pH 8.0 with 48 μL of 3.0 μM anti-DNP (coumarin dye A-PEG 12 )7-biotin and 31.5 μL of 13.7 μM SA (cyanine dye B)7 (3 molar equivalents) were used to assemble a two-protein system to form an anti-DNP (coumarin dye A-PEG 12 )7-biotin-[SA(cyanine dye B)7]3. The double protein complex was characterized by nanodrop spectrometer.

[0330] Example 3. Two-label SBS with unlabeled nucleotides

[0331] In this embodiment, SBS is performed using a two-dye scheme with a universal ffN having two different hapten parts. The unlabeled ffN used in the incorporation mixture includes dark ffG, biotin-linked ffA (ffA-sPA-LN3-biotin), DNP-linked ffA (ffA-sPA-LN3-DNP), DNP-linked ffT (ffT-LN3-DNP), biotin-linked ffC (ffC-LN3-LN3-biotin) and SO7181-linked ffC (ffC-LN3-SO7181). SO7181 is a commercially available red dye. After incorporation of unlabeled nucleotides, the affinity reagent mixture for secondary labeling includes 0.1 μM anti-DNP antibody labeled with coumarin dye A (anti-DNP (coumarin dye A) 4), and 0.1 μM streptavidin labeled with cyanine dye B. The affinity reagent mixture is introduced into the incorporated ffN and allowed to bind at 60°C for 60 seconds. SBS runs were performed on the MiSeq using blue light excitation / green light excitation (blue light at approximately 460 nm first, followed by green light at approximately 532 nm).

[0332] Figure 3Ais a dual dye SBS signal intensity scatter plot generated from the readout of an SBS run incorporating cycle 26. Channel 1 (x-axis) plots the intensity of the green channel, while channel 2 (y-axis) plots the intensity of the blue channel. In the run, the average error rate for 150 cycles was 1.1%, the average phase was 0.07%, and the average signal remaining was 61%.

[0333] A second SBS run was performed under similar conditions with a reverse labeled protein tag, which included 0.1 μM anti-DNP antibody labeled with cyanine dye B and 0.1 μM streptavidin labeled with coumarin dye A. Figure 3B is a dual dye SBS intensity plot generated from the readout of the run spike cycle 26. Channel 1 (x-axis) plots the intensity of the blue channel, while channel 2 (y-axis) plots the intensity of the green channel. For this run, the error rate was 0.54%, the phase was 0.13%, and the signal remaining was 63%.

[0334] Example 4. Triple-label SBS with unlabeled nucleotides

[0335] In this embodiment, SBS is performed using a three-label system having an unlabeled nucleotide set with three different hapten moieties. The ffn used includes dark ffG, ffA (ffA-sPA-LN3-DNP) connected by DNP, ffC (ffC-LN3-LN3-biotin) connected by biotin, and ffT (ffT-sPA-LN3-DIG) connected by DIG. The affinity reagent mixture (i.e., the labeled protein mixture) includes the double-labeled streptavidin complex SA (coumarin dye A-PEG) as described in Example 1. 12 ) 4.5 (Cyanine dye B ) 1.4 , including an average of 4.5 molar equivalents of coumarin dye A part (blue dye) and 1.4 molar equivalents of cyanine dye B (green dye); anti-DIG antibody labeled with cyanine dye B (anti-DIG (cyanine dye B) 8) and anti-DNP antibody labeled with coumarin dye A (anti-DNP (coumarin dye A) 4). The labeled protein mixture was introduced into the spiked ffN and bound at 60°C for 60 seconds. Blue light excitation / green light excitation was used in MiSeq TM SBS is run on.

[0336] Figure 4A is a scatter plot of the dual dye SBS signal intensity generated from the run spike cycle 1. Channel 1 (x-axis) plots the intensity of the green channel, while channel 2 (y-axis) plots the intensity of the blue channel. For the run, the error rate at cycle 150 was 0.79%, the phase was 0.059%, and the signal remaining was 86%.

[0337] Under similar conditions, a second SBS run was performed with a different affinity reagent mixture. The ffn incorporated into the mixture included: dark ffG, ffA (ffA-sPA-LN3-DNP) connected to DNP, ffC (ffC-LN3-LN3-biotin) connected to biotin, and ffT (ffT-sPA-LN3-DIG) connected to DIG. The affinity reagent mixture (i.e., the labeled protein mixture) included the dual protein assembly system described in Example 2 - anti-DNP (coumarin dye A-PEG 12 )7-biotin-[SA (cyanine dye B)7]3. Anti-DNP antibody is covalently labeled with coumarin dye A part (blue dye). In addition, anti-DNP antibody is connected to the streptavidin labeled with three molar equivalents of cyanine dye B (green dye) via biotin linker. These streptavidin molecules are labeled with an average of 7 cyanine dye B parts, and any remaining biotin binding site is blocked so that the protein assembly cannot be combined with the WC connected with biotin. The labeled protein mixture also includes anti-DIG antibody (anti-DIG (cyanine dye B)8) labeled with cyanine dye B and streptavidin (SA (coumarin dye A)4) labeled with coumarin dye A.

[0338] Figure 4B It is a scatter plot of the double dye SBS signal intensity generated from the second run incorporation cycle 1. Channel 1 (x-axis) plots the intensity of the blue channel, while channel 2 (y-axis) plots the intensity of the green channel. In addition, it is observed that there is no channel 1-channel 2 anti-correlated sequence environment behavior of A cloud in the scatter plot (when ffA is labeled with a blue dye or a green dye, it is usually observed in two-channel SBS) because each of ffA, ffC and ffT has a single entity label.

[0339] Example 5. Synthesis and Fluorescence Intensity Solution Data of Hydrophilic Coumarin Dye of Formula (I)

[0340]

[0341] 3-Amino-4-hydroxybenzoic acid (4.05 g, 26.5 mmol, 1.0 eq) was suspended in ethanol (50 ml) and cooled to 0 ° C. Ethyl 3-ethoxy-3-iminopropanoate hydrochloride (5.69 g, 29.1 mmol, 1.1 eq) was added, and the flask was warmed to room temperature and then heated to reflux for 16 hours. The reaction mixture was cooled to room temperature, and the precipitate formed was collected by filtration and washed with EtOH. The collected target compound 1 was an off-white powder (5.99 g, 24.1 mmol, 91%). 1H NMR (400MHz, DMSO) δ13.12(s,<1H),8.26(d,J=1.6Hz,1H),8.03(dd,J=8.5,1.7Hz,1 H), 7.84 (d, J = 8.5Hz, 1H), 4.27 (s, 2H), 4.17 (q, J = 7.1Hz, 2H), 1.21 (t, J = 7.1Hz, 3H).

[0342]

[0343] 4-Fluoro-2-hydroxybenzaldehyde (3.35 g, 23.9 mmol, 1.0 equivalent) and compound 1 (5.97 g, 23.9 mmol, 1.0 equivalent) were suspended in EtOH, followed by the addition of AcOH (836 μl, 12.0 mmol, 0.5 equivalent) and piperidine (974 μl, 12.0 mmol, 0.5 equivalent). The reactants were heated to reflux for 16 hours (forming an orange suspension, heated to dissolve). The reaction mixture was cooled to room temperature, and the precipitate was collected by filtration, washed with EtOH and dried under high vacuum to give compound 2 (5.05 g, 15.5 mmol, 65%) in the form of a pale yellow solid. 1H NMR (400MHz, DMSO) δ9.13 (s, 1H), 8.29 (d, J = 1.5Hz, 1H), 8.15–8.03 (m, 2H), 7. 80(d,J=8.5Hz,1H), 7.52(dd,J=9.6,2.5Hz,1H), 7.38(td,J=8.8,2.5Hz,1H).

[0344] Synthesis of Dye I-1

[0345]

[0346] Compound 3 (53.5 mg, 190 μmol, 2.0 equivalents) and compound 2 (30.9 mg, 95 μmol, 1.0 equivalents) were suspended in DMSO (2 ml). DIPEA (165 μl, 950 μmol, 10.0 equivalents) was added and the reaction was heated at 110 ° C for 16 hours (orange suspension to dark orange solution). Half the volume of solvent was distilled off under high vacuum at 60 ° C, and the residue was diluted with a 1:1 mixture of water and acetonitrile (10 ml). The product was purified by preparative HPLC (eluted with 35% acetonitrile / water) to obtain dye I-1 (31.3 μmol, 33%), λ abs =450nm,λ fl =495nm.

[0347] Synthesis of Dye I-2

[0348]

[0349] A solution of 3-amino-1-propanesulfonic acid (0.75 g, 5.39 mmol, 1.0 eq) in water (5 ml) was heated to 60° C. Aqueous NaOH (2 M, 3 ml) was added, followed by dropwise addition of a solution of sodium 3-bromopropanesulfonate (1.40 g, 6.22 mmol, 1.15 eq) in water (5 ml) and stirred at 60° C. for 16 hours. The reaction mixture was evaporated and redissolved in a minimum volume of water and purified by C18 column chromatography (0%-10% acetonitrile / water) to give compound 4 as a crude mixture with undesired primary and tertiary amines (not reacted in the next step).

[0350]

[0351] Compound 4 (2.0 g crude mixture) and compound 2 (750 mg, 2.31 mmol, 1.0 equiv) were suspended in DMSO (40 ml). DIPEA (4.0 ml, 23.1 mmol, 10.0 equiv) was added and the reaction was heated at 110 ° C for 16 hours (orange suspension to dark orange solution). Half the volume of solvent was distilled off under 60 ° C high vacuum, the residue was diluted with water (40 ml) and filtered. Dye I-2 was purified by preparative HPLC (eluted in 20% acetonitrile / water) to obtain dye I-2 (187 μmol, 8%), λ abs =449nm,λ fl =494nm.

[0352] General Synthesis of Amine-Modified Coumarin Dyes

[0353]

[0354] Amine R1-NH-R2 (2.0 equivalents) and compound 2 (1.0 equivalents) were suspended in DMSO. DIPEA (10.0 equivalents) was added and the reaction was heated at 110°C for 6-16 hours (orange suspension to dark orange solution). Half the volume of solvent was distilled off under high vacuum at 60°C, the residue was diluted with water and filtered. The product was purified by preparative HPLC (eluted with 20%-40% acetonitrile / water) to obtain amine-modified coumarin dyes (8%-40% yield). Dye I-4 was prepared in 40% yield using the general synthetic method described herein, λabs=451nm, λfl=500nm.

[0355] The fluorescence intensity of dye I-1 and dye I-2 was tested in solution relative to the reference coumarin dye C, which is a standard blue dye used in Illumina's two-channel SBS and has good stability and fluorescence intensity. In addition, proteins / antibodies labeled with various dyes I-1 and dye I-2 (such as streptavidin, anti-DIG, anti-DNP) were also prepared according to the similar procedures described in Example 1 and tested for their fluorescence intensity in solution. Figure 5A and Figure 5B As shown, the labeled streptavidin, labeled anti-DIG and labeled anti-DNP showed greater fluorescence intensity in solution compared with ffA labeled with the same concentration of coumarin dye C.

[0356] Example 6. Hydrophilic coumarin dyes using formula (I) SBS

[0357] ffC-sPA-dye I-1 and ffC-sPA-dye I-2 were used in Illumina MiSeq TM The test was conducted on a 100 nm platform with blue and green LEDs operating at 460 nm and 532 nm, respectively, compared with the standard ffC-sPA-coumarin dye C. The sequencing protocol used 22°C scanning, no variable dose, no reuse, 25 s incorporation time, and 10 s cleavage time. In addition to the labeled ffC, the additional components of the incorporation mixture included: (1) a nucleotide set including dark G, ffC-SO7181, ffA-LN3-BL-coumarin dye C, ffA-BL-NR550S0 (a known green dye), ffT-LN3-cyanine dye B; (2) DNA polymerase Pol 1901; and (3) glycine buffer.

[0358] FIG. 6A to FIG. 6C It is blue / green dual channel in the 5th cycle Scatter plot of SBS runs comparing the effect of altering ffC-sPA-coumarin dye C with ffC-sPA-dye 1-1 or ffC-sPA-dye 1-2. Compared to standard ffC labeled with coumarin dye C, ffC-sPA-dye 1-1 or ffC-sPA-dye 1-2 show increased brightness in sequencing.

[0359] When exposed to increasing doses during sequencing, ffN mixtures incorporating ffC-sPA-Dye 1-2 and ffC-sPA-Dye 1-4 both retained more signal than the corresponding ffC-sPA-Coumarin Dye C ( Fig. 7A and Figure 7B ). This may indicate that during each cycle of the sequencing process, the growing DNA strand is less damaged by these ffns.

Claims

1. A kit for sequencing applications, comprising: a first type of unlabeled nucleotides, the first type of unlabeled nucleotides comprising a first hapten; a second type of unlabeled nucleotides, said second type of unlabeled nucleotides comprising a second hapten; a third type of unlabeled nucleotides; and A set of affinity reagents, the set of affinity reagents comprising: a first affinity reagent comprising a first hapten binding partner capable of specifically binding to the first type of unlabeled nucleotides; and a second affinity reagent comprising a second hapten binding partner capable of specifically binding to the second type of unlabeled nucleotides; wherein the first affinity reagent comprises one or more first detectable labels, the one or more first detectable labels being capable of being excited by a first excitation light source, the second affinity reagent comprises one or more second detectable labels, the one or more second detectable labels being capable of being excited by a second excitation light source, and wherein the first detectable label and the second detectable label are spectrally distinguishable; and One of the first excitation light source and the second excitation light source has a wavelength of about 450 nm to about 460 nm, and the other of the first excitation light source and the second excitation light source has a wavelength of about 520 nm to about 540 nm. 2 . The kit of claim 1 , wherein the first hapten is covalently linked to a nucleobase of the first type of unlabeled nucleotide via a cleavable linker.

3. The kit according to claim 1 or 2, wherein the second hapten is covalently linked to the nucleobase of the second type of unlabeled nucleotide via a cleavable linker.

4. The kit according to any one of claims 1 to 3, wherein the third type of unlabeled nucleotides comprises a mixture of the third type of unlabeled nucleotides containing the first hapten and the third type of unlabeled nucleotides containing the second hapten, and wherein both the first affinity reagent and the second affinity reagent are capable of specifically binding to the third type of unlabeled nucleotides.

5. The kit of claim 4, wherein each of the first hapten and the second hapten is covalently linked to a nucleobase of the third type of nucleotide via a cleavable linker.

6. The kit of claim 4 or 5, wherein the first hapten comprises a biotin moiety and the first hapten binding partner comprises avidin.

7. The kit according to claim 6, wherein the avidin is streptavidin or neutravidin.

8. The kit according to claim 6 or 7, wherein one or more biotin binding sites of the avidin are blocked by a molecule containing a biotin moiety or an analog thereof.

9. The kit according to any one of claims 6 to 8, wherein the second hapten comprises a dinitrophenyl (DNP) moiety and the second hapten binding partner comprises an anti-DNP antibody.

10. The kit according to claim 9, wherein the third type of unlabeled nucleotides comprises a mixture of the third type of unlabeled nucleotides containing a biotin moiety and the third type of unlabeled nucleotides containing a DNP moiety.

11. The kit according to any one of claims 6 to 8, wherein the second hapten comprises a digoxigenin (DIG) moiety and the second hapten binding partner comprises an anti-DIG antibody.

12. The kit according to claim 11, wherein the third type of unlabeled nucleotides comprises a mixture of a third type of unlabeled nucleotides containing a biotin moiety and a third type of unlabeled nucleotides containing a DIG moiety.

13. The kit according to any one of claims 1 to 3, wherein the third type of unlabeled nucleotides comprises a third hapten, and the set of affinity reagents further comprises a third affinity reagent comprising a third hapten binding partner capable of specifically binding to the third hapten.

14. The kit of claim 13, wherein the third hapten is covalently linked to the nucleobase of the third type of unlabeled nucleotide via a cleavable linker.

15. The kit of claim 13 or 14, wherein the first hapten comprises a biotin moiety and the first hapten binding partner comprises avidin.

16. The kit according to claim 15, wherein the avidin is streptavidin or neutravidin.

17. The kit according to claim 15 or 16, wherein one or more biotin binding sites of the avidin are blocked by a molecule containing a biotin moiety or an analogue thereof.

18. The kit according to any one of claims 15 to 17, wherein one of the second hapten and the third hapten comprises a DNP moiety and the other of the second hapten and the third hapten comprises a DIG moiety.

19. The kit of claim 13 or 14, wherein one of the first hapten and the second hapten comprises a DNP moiety and the other of the first hapten and the second hapten comprises a DIG moiety.

20. The kit of claim 19, wherein the third hapten comprises a biotin moiety and the third hapten binding partner comprises avidin.

21. The kit of claim 20, wherein the avidin is streptavidin or neutravidin.

22. The kit of claim 20 or 21, wherein one or more biotin binding sites of the avidin are blocked with a molecule containing a biotin moiety or an analog thereof.

23. The kit of any one of claims 13 to 22, wherein the third affinity reagent comprises one or more first detectable labels and one or more second detectable labels.

24. The kit according to claim 23, wherein the third affinity reagent comprises the multi-dye-labeled protein assembly system according to any one of claims 29 to 42.

25. The kit according to any one of claims 1 to 24, further comprising a fourth type of unlabeled nucleotides, wherein the fourth type of unlabeled nucleotides cannot specifically bind to any of the affinity reagents.

26. The kit of claim 25, wherein each of the first type of unlabeled nucleotides, the second type of unlabeled nucleotides, the third type of unlabeled nucleotides, and the fourth type of unlabeled nucleotides comprises a 3' blocking group.

27. The kit according to any one of claims 1 to 26, wherein the first detectable label is a dye having a structure of formula (I): in R 1 is -C(O)OC1-C6 alkyl, -SO3H, -OH, optionally substituted 5- to 10-membered heteroaryl, optionally substituted 3- to 10-membered heterocyclyl, optionally substituted phenyl, or -OR x ; R x is optionally substituted 5- to 10-membered heteroaryl, optionally substituted 3- to 10-membered heterocyclyl, or optionally substituted phenyl; m is an integer of 1, 2 or 3; and n is an integer of 1, 2, 3, 4 or 5.

28. The kit according to any one of claims 1 to 27, further comprising a DNA polymerase and one or more buffer compositions.

29. A protein assembly system, comprising: a first protein, wherein the first protein is labeled with one or more first detectable labels; one or more hapten-containing linkers, wherein the one or more hapten-containing linkers are covalently attached to the first protein; as well as one or more hapten-binding second proteins, the one or more hapten-binding second proteins being bound to one or more hapten-containing linkers; wherein the one or more hapten-bound second proteins are labeled with one or more second detectable labels, and wherein the one or more first detectable labels are spectrally distinguishable from the one or more second detectable labels.

30. The protein assembly system of claim 29, wherein the one or more hapten-containing linkers are linkers containing a biotin moiety, and the one or more hapten-binding second proteins are biotin-binding proteins.

31. The protein assembly system of claim 29 or 30, wherein the one or more hapten-binding second proteins comprise avidin.

32. The protein assembly system of claim 31, wherein the avidin is streptavidin or neutravidin.

33. A protein assembly system according to claim 31 or 32, wherein one or more biotin binding sites of the avidin protein are blocked by a molecule containing a biotin moiety or an analog thereof.

34. The protein assembly system of any one of claims 29 to 33, wherein the first protein comprises an antibody.

35. The protein assembly system of claim 34, wherein the antibody is an anti-DNP antibody or an anti-DIG antibody.

36. A protein assembly system according to any one of claims 29 to 35, wherein the one or more first detectable labels can be excited by blue light and the one or more second detectable labels can be excited by green light.

37. A protein assembly system according to any one of claims 29 to 35, wherein the one or more first detectable labels can be excited by green light and the one or more second detectable labels can be excited by blue light.

38. A protein assembly system according to claim 36 or 37, wherein the blue light has a wavelength of about 450nm to about 460nm.

39. The protein assembly system of claim 36 or 37, wherein the green light has a wavelength of about 520 nm to about 540 nm.

40. The protein assembly system of any one of claims 29 to 39, wherein the first protein is labeled with a plurality of first detectable labels.

41. The protein assembly system of any one of claims 30 to 40, wherein the protein assembly system comprises at least two biotin-binding proteins, each biotin-binding protein being labeled with a plurality of second detectable labels.

42. A protein assembly system according to any one of claims 30 to 41, wherein the linker containing the biotin moiety comprises a PEG repeating unit (—OCH2CH2—) n , and wherein n is an integer from 2 to 30.

43. The protein assembly system of any one of claims 29 to 42, wherein the one or more first detectable labels comprise a coumarin dye having a structure of formula (I): in R 1 is -C(O)OC1-C6 alkyl, -SO3H, -OH, optionally substituted 5- to 10-membered heteroaryl, optionally substituted 3- to 10-membered heterocyclyl, optionally substituted phenyl, or -OR x ; R x is optionally substituted 5- to 10-membered heteroaryl, optionally substituted 3- to 10-membered heterocyclyl, or optionally substituted phenyl; m is an integer of 1, 2 or 3; and n is an integer of 1, 2, 3, 4 or 5.

44. A nucleotide complex comprising the protein assembly system according to any one of claims 29 to 43.

45. The nucleotide complex of claim 44, wherein the protein assembly system is bound to a hapten portion of the nucleotide, and wherein the hapten portion of the nucleotide is capable of specifically binding to at least one of the proteins of the protein assembly system.

46. ​​The nucleotide complex of claim 45, wherein the hapten portion of the nucleotide comprises a DIG portion or a DNP portion.

47. The nucleotide complex of any one of claims 44 to 46, wherein the hapten portion of the nucleotide is covalently linked to a nucleobase via a cleavable linker.

48. An oligonucleotide or polynucleotide comprising a nucleotide complex according to any one of claims 44 to 47 incorporated therein.

49. The oligonucleotide or polynucleotide of claim 48, wherein the oligonucleotide or polynucleotide is at least partially complementary to and hybridizes to a target polynucleotide immobilized on the surface of a solid support.

50. The oligonucleotide or polynucleotide of claim 48 or 49, wherein the solid support comprises a plurality of immobilized target polynucleotides, wherein the density of the immobilized target polynucleotides on the solid support is at least about 50,000 / mm 2 .

51. A method for determining the sequence of a plurality of different target polynucleotides, the method comprising: (a) contacting a solid support with a solution containing a sequencing primer under hybridization conditions, wherein the solid support comprises a plurality of different target polynucleotides immobilized thereon; and the sequencing primer is complementary to at least a portion of the target polynucleotide; (b) contacting the solid support with an aqueous solution comprising a DNA polymerase and one or more of four different types of unlabeled nucleotides under conditions suitable for DNA polymerase-mediated primer extension, and incorporating one type of nucleotide into the sequencing primer to produce an extended copy polynucleotide; in Each of the four types of nucleotides comprises a 3' blocking group; The first type of unlabeled nucleotides comprises a first hapten; The second type of unlabeled nucleotides comprises a second hapten; (c) contacting the extended copy polynucleotide with a set of affinity reagents under conditions where one of the affinity reagents specifically binds to the incorporated unlabeled nucleotide to provide a labeled extended copy polynucleotide; (d) imaging the solid support and performing one or more fluorescence measurements of the extended copy polynucleotide; and (e) removing the 3' blocking group of the incorporated nucleotide; wherein the set of affinity reagents comprises: a first affinity reagent comprising a first hapten binding partner capable of specifically binding to the first type of unlabeled nucleotides; and a second affinity reagent comprising a second hapten binding partner capable of specifically binding to the second type of unlabeled nucleotides; wherein the first affinity reagent comprises one or more first detectable labels, the one or more first detectable labels being capable of being excited by a first excitation light source, the second affinity reagent comprises one or more second detectable labels, the one or more second detectable labels being capable of being excited by a second excitation light source, and wherein the one or more first detectable labels are spectrally distinguishable from the one or more second detectable labels; and One of the first excitation light source and the second excitation light source has a wavelength of about 450 nm to about 460 nm, and the other of the first excitation light source and the second excitation light source has a wavelength of about 520 nm to about 540 nm.

52. The method of claim 51, wherein the first hapten is covalently attached to a nucleobase of the first type of unlabeled nucleotide via a cleavable linker.

53. The method of claim 51 or 52, wherein the second hapten is covalently linked to a nucleobase of the second type of unlabeled nucleotide via a cleavable linker.

54. The method of any one of claims 51 to 53, wherein the third type of unlabeled nucleotides comprises a mixture of the third type of unlabeled nucleotides containing the first hapten and the third type of unlabeled nucleotides containing the second hapten, and wherein both the first affinity reagent and the second affinity reagent are capable of specifically binding to the third type of unlabeled nucleotides.

55. The method of claim 54, wherein each of the first hapten and the second hapten is covalently linked to a nucleobase of the third type of nucleotide via a cleavable linker.

56. The method of claim 54 or 55, wherein the first hapten comprises a biotin moiety and the first hapten binding partner comprises avidin.

57. The method of claim 56, wherein the avidin is streptavidin or neutravidin.

58. The method of claim 56 or 57, wherein one or more biotin binding sites of the avidin are blocked with a molecule containing a biotin moiety or an analog thereof.

59. The method of any one of claims 56 to 58, wherein the second hapten comprises a DNP moiety and the second hapten binding partner comprises an anti-DNP antibody.

60. The method of claim 59, wherein the third type of unlabeled nucleotides comprises a mixture of a third type of unlabeled nucleotides containing a biotin moiety and a third type of unlabeled nucleotides containing a DNP moiety.

61. The method of any one of claims 56 to 58, wherein the second hapten comprises a DIG moiety and the second hapten binding partner comprises an anti-DIG antibody.

62. The method of claim 61, wherein the third type of unlabeled nucleotides comprises a mixture of a third type of unlabeled nucleotides containing a biotin moiety and a third type of unlabeled nucleotides containing a DIG moiety.

63. The method of any one of claims 51 to 53, wherein the third type of unlabeled nucleotides comprises a third hapten, and the set of affinity reagents further comprises a third affinity reagent comprising a third hapten binding partner capable of specifically binding to the third hapten.

64. The method of claim 63, wherein the third hapten is covalently attached to a nucleobase of the third type of unlabeled nucleotide via a cleavable linker.

65. The method of claim 63 or 64, wherein the first hapten comprises a biotin moiety and the first hapten binding partner comprises avidin.

66. The method of claim 65, wherein one of the second hapten and the third hapten comprises a DNP moiety and the other of the second hapten and the third hapten comprises a DIG moiety.

67. The method of claim 63 or 64, wherein one of the first hapten and the second hapten comprises a DNP moiety and the other of the first hapten and the second hapten comprises a DIG moiety.

68. The method of claim 67, wherein the third hapten comprises a biotin moiety and the third hapten binding partner comprises avidin.

69. The method of claim 65 or 68, wherein the avidin is streptavidin or neutravidin.

70. The method of claim 68 or 69, wherein one or more biotin binding sites of the avidin are blocked with a molecule containing a biotin moiety or an analog thereof.

71. The method of any one of claims 63 to 70, wherein the third affinity reagent comprises one or more first detectable labels and one or more second detectable labels.

72. The method of claim 71, wherein the third affinity reagent comprises a multi-dye labeled protein assembly system according to any one of claims 29 to 42.

73. The method of any one of claims 51 to 72, further comprising a fourth type of unlabeled nucleotides, wherein the fourth type of unlabeled nucleotides cannot specifically bind to any of the affinity reagents.

74. A method according to any one of claims 51 to 73, wherein step (e) also removes the detectable label of the incorporated nucleotide.

75. The method of claim 74, wherein the detectable label and the 3' blocking group of the incorporated nucleotide are removed in a single chemical reaction.

76. The method of any one of claims 51 to 75, further comprising (f) washing the solid support with an aqueous washing solution.

77. The method of claim 76, wherein steps (b) to (f) are repeated for at least 50, 100, 150, 200, 250, 300, 400 or 500 cycles to determine the target polynucleotide sequence.

78. The method of any one of claims 51 to 77, wherein the four types of nucleotides include dATP, dCTP, dGTP and dTTP or dUTP or non-natural nucleotide analogs thereof.

79. The method of any one of claims 51 to 78, wherein the density of the immobilized target polynucleotides on the solid support is at least about 50,000 / mm 2 .

80. The method of any one of claims 51 to 79, wherein the method reduces or eliminates sequence environment effects.

81. A labeled nanoparticle, the labeled nanoparticle comprising: A polymer matrix comprising a plurality of detectable labels, wherein the backbone of the polymer comprises one or more cleavable moieties, and wherein the labeled nanoparticles are capable of being degraded into smaller polymeric chains upon cleavage of the cleavable moieties.

82. A labeled nanoparticle according to claim 81, wherein the plurality of detectable labels comprises a fluorophore capable of being excited by a light source having a wavelength between about 450 nm and about 460 nm.

83. The labeled nanoparticles of claim 81 or 82, wherein the smaller polymeric chains of the degraded nanoparticles are water soluble.

84. A labeled nanoparticle according to any one of claims 81 to 83, wherein the cleavable portion is chemically degradable, enzymatically degradable, thermally degradable or photodegradable.

85. A labeled nanoparticle according to any one of claims 81 to 84, wherein the cleavable portion comprises a disulfide, an azido or an allyl portion, or a combination thereof.

86. A labeled nanoparticle according to any one of claims 81 to 85, wherein the polymer comprises a cross-linked or dendritic polymer or a liposome.

87. The labeled nanoparticle of any one of claims 81 to 86, wherein the polymer comprises polyacrylamide, polyglycolic acid (PGA), polyvinyl alcohol (PVA).

88. A labeled nanoparticle according to any one of claims 81 to 88, wherein the multiple detectable labels are covalently attached to the polymer matrix.

89. A labeled nanoparticle according to any one of claims 81 to 88, wherein the multiple detectable labels are encapsulated or physically confined within the polymer matrix.

90. The labeled nanoparticle of any one of claims 81 to 89, comprising one or more proteins attached thereto.

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