Compositions, methods, and systems are provided for fluorescent polymerase enzyme substrates comprising protein shields for improving enzyme photostability in single molecule real time sequencing. Fluorescent polymerase enzyme substrates of the invention have a protein shield between the fluorescent dye moieties and nucleotide moieties of the polymerase enzyme substrate. The polymerase enzyme substrates have a nucleotide component and a dye component, each attached to a protein. The attachments can be covalent. The protein can, for example, prevent the direct interaction of the fluorescent dye moiety with the enzyme when carrying out nucleotide synthesis, preventing photodamage to the enzyme. The polymerase enzyme substrates of the invention can have multiple dyes and multiple nucleotide moieties.

Compositions, methods, and systems are provided for fluorescent polymerase enzyme substrates comprising protein shields for improving enzyme photostability in single molecule real time sequencing. Fluorescent polymerase enzyme substrates of the invention have a protein shield between the fluorescent dye moieties and nucleotide moieties of the polymerase enzyme substrate. The polymerase enzyme substrates have a nucleotide component and a dye component, each attached to a protein. The attachments can be covalent. The protein can, for example, prevent the direct interaction of the fluorescent dye moiety with the enzyme when carrying out nucleotide synthesis, preventing photodamage to the enzyme. The polymerase enzyme substrates of the invention can have multiple dyes and multiple nucleotide moieties.

Multivalent binding compositions including a particle-nucleotide conjugate having a plurality of copies of a nucleotide attached to the particle are described. The multivalent binding compositions allow one to localize detectable signals to active regions of biochemical interaction, e.g., sites of protein-protein interaction, protein-nucleic acid interaction, nucleic acid hybridization, or enzymatic reaction, and can be used to identify sites of base incorporation in elongating nucleic acid chains during polymerase reactions and to provide improved base discrimination for sequencing and array based applications.

Multivalent binding compositions including a particle-nucleotide conjugate having a plurality of copies of a nucleotide attached to the particle are described. The multivalent binding compositions allow one to localize detectable signals to active regions of biochemical interaction, e.g., sites of protein-protein interaction, protein-nucleic acid interaction, nucleic acid hybridization, or enzymatic reaction, and can be used to identify sites of base incorporation in elongating nucleic acid chains during polymerase reactions and to provide improved base discrimination for sequencing and array based applications.

Compositions, methods, and systems are provided for fluorescent polymerase enzyme substrates comprising protein shields for improving enzyme photostability in single molecule real time sequencing. Fluorescent polymerase enzyme substrates of the invention have a protein shield between the fluorescent dye moieties and nucleotide moieties of the polymerase enzyme substrate. The polymerase enzyme substrates have a nucleotide component and a dye component, each attached to a protein. The attachments can be covalent. The protein can, for example, prevent the direct interaction of the fluorescent dye moiety with the enzyme when carrying out nucleotide synthesis, preventing photodamage to the enzyme. The polymerase enzyme substrates of the invention can have multiple dyes and multiple nucleotide moieties.

Compositions, methods, and systems are provided for fluorescent polymerase enzyme substrates comprising protein shields for improving enzyme photostability in single molecule real time sequencing. Fluorescent polymerase enzyme substrates of the invention have a protein shield between the fluorescent dye moieties and nucleotide moieties of the polymerase enzyme substrate. The polymerase enzyme substrates have a nucleotide component and a dye component, each attached to a protein. The attachments can be covalent. The protein can, for example, prevent the direct interaction of the fluorescent dye moiety with the enzyme when carrying out nucleotide synthesis, preventing photodamage to the enzyme. The polymerase enzyme substrates of the invention can have multiple dyes and multiple nucleotide moieties.

The present disclosure provides methods and systems for processing a nucleotide mixture. A nucleotide mixture can be purified. A nucleotide mixture can be processed for use in nucleic acid synthesis. A nucleotide mixture can be processed for use in nucleic acid sequencing.

Embodiments of the present disclosure relate to cyclooctatetraene containing dyes and their uses as fluorescent labels. Also provided are composition containing cyclooctatetraene. The dyes and compositions may be used in various biological applications, such as nucleic acid sequencing.

Embodiments of the present disclosure relate to cyclooctatetraene containing dyes and their uses as fluorescent labels. Also provided are composition containing cyclooctatetraene. The dyes and compositions may be used in various biological applications, such as nucleic acid sequencing.

Provided herein are engineered variants of archaeal, prokaryotic, and eukaryotic polymerases that exhibit enhanced thermostability, enhanced incorporation of 3′ modified nucleotides, and improved uracil-tolerance, in polymerase-catalyzed nucleotide extension reactions relative to wild type polymerase enzymes. Also provided are uses of the engineered polymerases for forming complexed polymerases, forming binding complexes and forming ternary complexes, and uses for conducting nucleic acid sequencing reactions.