Abstract: Electrically controlled hybridization is used to selectively assemble oligonucleotides on the surface of a microelectrode array. Controlled activation of individual electrodes in the microelectrode array attracts oligonucleotides in solution to specific regions of the array where they hybridize to other oligonucleotides anchored on the array. The oligonucleotides that hybridize may provide locations for subsequent oligonucleotides to hybridize. The active electrodes and the oligonucleotides in solution may be varied during each round of synthesis. This allows for multiple oligonucleotides each with different and specific sequences to be created in parallel. This is accomplished without the use of phosphoramidite chemical synthesis or template-independent DNA polymerase enzymatic synthesis. Oligonucleotides created with these techniques may be used to encode digital data. Fully assembled oligonucleotides may be separated from the array and sequenced, stored, or otherwise processed.

Abstract: De novo polynucleotide synthesis is performed with a substrate-bound polymerase. The polymerase is attached to a solid substrate such as a microelectrode array. The polymerase adds nucleotides to growing polynucleotides strands that are also attached to the solid substrate. Spatial control of polymerase activity is achieved by changing the rate of nucleotide polymerization at selected locations on the surface of the solid substrate. The rate of polymerization is changed by inhibiting or promoting activity of the polymerase. In some implementations, activation of electrodes in the microelectrode array changes the rate of nucleotide polymerization. Nucleotides are added to the growing polynucleotide strands at areas where the polymerase is active. By varying the locations where the substrate-bound polymerase is active and the species of nucleotide added, a population of polynucleotides with different, arbitrary sequences is synthesized on the surface of the solid substrate.

Abstract: Array-based enzymatic oligonucleotide synthesis creates a large number of polynucleotides using an uncontrolled and template independent polymerase such as terminal deoxynucleotidyl transferase (TdT). Spatial control of reaction conditions on the surface of the array allows creation of polynucleotides with a variety of arbitrary sequences. Spatial control may be implemented by removing protecting groups attached to nucleotides only at a selected location on the array or by other techniques such as location-specific regulation of enzymatic activity. The ratio of polynucleotides with protecting groups to unprotected polynucleotides used during a cycle of synthesis is adjusted to control the length of homopolymers created by the polymerase. Digital information may be encoded in the enzymatically synthesized polynucleotides.

Abstract: Electrically controlled hybridization is used to selectively assemble oligonucleotides on the surface of a microelectrode array. Controlled activation of individual electrodes in the microelectrode array attracts oligonucleotides in solution to specific regions of the array where they hybridize to other oligonucleotides anchored on the array. The oligonucleotides that hybridize may provide locations for subsequent oligonucleotides to hybridize. The active electrodes and the oligonucleotides in solution may be varied during each round of synthesis. This allows for multiple oligonucleotides each with different and specific sequences to be created in parallel. This is accomplished without the use of phosphoramidite chemical synthesis or template-independent DNA polymerase enzymatic synthesis. Oligonucleotides created with these techniques may be used to encode digital data. Fully assembled oligonucleotides may be separated from the array and sequenced, stored, or otherwise processed.

Abstract: A switchable hydrophilic surface is created by attaching electrochemically switchable hydrophilicity polymers to the surface of a microelectrode array. Ferrocene polymers are one example of electrochemically switchable hydrophilicity polymers. Activation of electrodes in the microelectrode array changes the oxidation state of metal ions which switches the polymers between hydrophobic and hydrophilic conformations. Selective activation of electrodes can create patterns of wettability on the microelectrode array that may be varied in real time. The switchable hydrophilic surface may be used to control solid-phase synthesis of polymers. Growing polymers may be selectively extended at locations on the microelectrode array that are hydrophilic. The pattern of hydrophobic and hydrophilic regions can be changed during sequential rounds of synthesis to create a variety of different polymers at different locations on the surface of the microelectrode array.

Abstract: A universal template strand built with universal base analogs is used as a template for polynucleotide synthesis. The universal template strand can hybridize to any sequence of nucleotides. A new polynucleotide is synthesized by using a polymerase to extend a primer hybridized to the universal template strand. Unlike primer extension in polymerase chain reactions, base pairing with nucleotides in the template strand does not specify the sequence of the new polynucleotide. Instead, the sequence of the new polynucleotide is specified by the order of addition of protected nucleotides. After addition of a single species of protected nucleotide, the blocking group is removed and another protected nucleotide is added. The order of nucleotide addition can be varied to create any sequence. After synthesis, the polynucleotide can be dehybridized from the universal template strand. The universal template strand may then be reused to synthesize a different polynucleotide.

Abstract: Array-based enzymatic oligonucleotide synthesis creates a large number of polynucleotides using an uncontrolled and template independent polymerase such as terminal deoxynucleotidyl transferase (TdT). Spatial control of reaction conditions on the surface of the array allows creation of polynucleotides with a variety of arbitrary sequences. Spatial control may be implemented by removing protecting groups attached to nucleotides only at a selected location on the array or by other techniques such as location-specific regulation of enzymatic activity. The ratio of polynucleotides with protecting groups to unprotected polynucleotides used during a cycle of synthesis is adjusted to control the length of homopolymers created by the polymerase. Digital information may be encoded in the enzymatically synthesized polynucleotides.

Abstract: This disclosure describes a technique for performing random access in a pool of polynucleotides by using one unique primer and one homopolymer primer to selectively amplify some but not all of the polynucleotides in the pool. The polynucleotides are synthesized by a template independent polymerase such as terminal deoxynucleotide transferase (TdT) rather than by phosphoramidite synthesis. Enzymatic synthesis efficiently creates homopolymer sequences through unregulated synthesis. Use of one homopolymer primer instead of two unique primers decreases the complexity, time, and cost of synthesizing the polynucleotides. Use of a unique primer provides a sequence that can be varied to uniquely identify multiple different groups of polynucleotides. This enables random access by polymerase chain reaction (PCR) amplification while still benefiting from the efficiency of homopolymer synthesis. The polynucleotides may include payload regions that use a sequence of nucleotides to encode digital data.

Abstract: A universal template strand built with universal base analogs is used as a template for polynucleotide synthesis. The universal template strand can hybridize to any sequence of nucleotides. A new polynucleotide is synthesized by using a polymerase to extend a primer hybridized to the universal template strand. Unlike primer extension in polymerase chain reactions, base pairing with nucleotides in the template strand does not specify the sequence of the new polynucleotide. Instead, the sequence of the new polynucleotide is specified by the order of addition of protected nucleotides. After addition of a single species of protected nucleotide, the blocking group is removed and another protected nucleotide is added. The order of nucleotide addition can be varied to create any sequence. After synthesis, the polynucleotide can be dehybridized from the universal template strand. The universal template strand may then be reused to synthesize a different polynucleotide.

Abstract: De novo polynucleotide synthesis is performed with a substrate-bound polymerase. The polymerase is attached to a solid substrate such as a microelectrode array. The polymerase adds nucleotides to growing polynucleotides strands that are also attached to the solid substrate. Spatial control of polymerase activity is achieved by changing the rate of nucleotide polymerization at selected locations on the surface of the solid substrate. The rate of polymerization is changed by inhibiting or promoting activity of the polymerase. In some implementations, activation of electrodes in the microelectrode array changes the rate of nucleotide polymerization. Nucleotides are added to the growing polynucleotide strands at areas where the polymerase is active. By varying the locations where the substrate-bound polymerase is active and the species of nucleotide added, a population of polynucleotides with different, arbitrary sequences is synthesized on the surface of the solid substrate.

Abstract: This disclosure describes a technique for performing random access in a pool of polynucleotides by using one unique primer and one homopolymer primer to selectively amplify some but not all of the polynucleotides in the pool. The polynucleotides are synthesized by a template independent polymerase such as terminal deoxynucleotide transferase (TdT) rather than by phosphoramidite synthesis. Enzymatic synthesis efficiently creates homopolymer sequences through unregulated synthesis. Use of one homopolymer primer instead of two unique primers decreases the complexity, time, and cost of synthesizing the polynucleotides. Use of a unique primer provides a sequence that can be varied to uniquely identify multiple different groups of polynucleotides. This enables random access by polymerase chain reaction (PCR) amplification while still benefitting from the efficiency of homopolymer synthesis. The polynucleotides may include payload regions that use a sequence of nucleotides to encode digital data.

Abstract: De novo polynucleotide synthesis is performed with a substrate-bound polymerase. The polymerase is attached to a solid substrate such as a microelectrode array. The polymerase adds nucleotides to growing polynucleotides strands that are also attached to the solid substrate. Spatial control of polymerase activity is achieved by changing the rate of nucleotide polymerization at selected locations on the surface of the solid substrate. The rate of polymerization is changed by inhibiting or promoting activity of the polymerase. In some implementations, activation of electrodes in the microelectrode array changes the rate of nucleotide polymerization. Nucleotides are added to the growing polynucleotide strands at areas where the polymerase is active. By varying the locations where the substrate-bound polymerase is active and the species of nucleotide added, a population of polynucleotides with different, arbitrary sequences is synthesized on the surface of the solid substrate.

Abstract: Polymers synthesized by solid-phase synthesis are selectively released from a solid support by reversing the bias of spatially addressable electrodes. Change in the current and voltage direction at one or more of the spatially addressable electrodes changes the ionic environment which triggers cleavage of linkers that leads to release of the attached polymers. The spatially addressable electrodes may be implemented as CMOS inverters embedded in an integrated circuit (IC). The IC may contain an array of many thousands of spatially addressable electrodes. Control circuity may independently reverse the bias on any of the individual electrodes in the array. This provides fine-grained control of which polymers are released from the solid support. Examples of polymers that may be synthesized on this type of array include oligonucleotides and peptides.

Abstract: This disclosure provides techniques and systems for efficient random access to digital data encoded in oligonucleotides (e.g., DNA). Random access to DNA-encoded data is provided by amplification using polymerase chain reaction (PCR) and primer pairs that selectively amplify only the oligonucleotides encoding a desired set of digital data. Multiple separate random-access requests are prepared for multiplex DNA sequencing by generating copy-normalized amplification products. Copy-normalized amplification products are efficiently created by performing multiple singleplex PCR reactions in parallel and measuring the quantity of oligonucleotides in each reaction. The PCR reactions are performed in parallel through the use of multiple isolated reaction volumes such as water-in-oil microdroplets or individual wells on a plate.

Abstract: This disclosure provides techniques and systems for efficient random access to digital data encoded in oligonucleotides (e.g., DNA). Random access to DNA-encoded data is provided by amplification using polymerase chain reaction (PCR) and primer pairs that selectively amplify only the oligonucleotides encoding a desired set of digital data. Multiple separate random-access requests are prepared for multiplex DNA sequencing by generating copy-normalized amplification products. Copy-normalized amplification products are efficiently created by performing multiple singleplex PCR reactions in parallel and measuring the quantity of oligonucleotides in each reaction. The PCR reactions are performed in parallel through the use of multiple isolated reaction volumes such as water-in-oil microdroplets or individual wells on a plate.

Abstract: A switchable hydrophilic surface is created by attaching electrochemically switchable hydrophilicity polymers to the surface of a microelectrode array. Ferrocene polymers are one example of electrochemically switchable hydrophilicity polymers. Activation of electrodes in the microelectrode array changes the oxidation state of metal ions which switches the polymers between hydrophobic and hydrophilic conformations. Selective activation of electrodes can create patterns of wettability on the microelectrode array that may be varied in real time. The switchable hydrophilic surface may be used to control solid-phase synthesis of polymers. Growing polymers may be selectively extended at locations on the microelectrode array that are hydrophilic. The pattern of hydrophobic and hydrophilic regions can be changed during sequential rounds of synthesis to create a variety of different polymers at different locations on the surface of the microelectrode array.

Abstract: De novo polynucleotide synthesis is performed with a substrate-bound polymerase. The polymerase is attached to a solid substrate such as a microelectrode array. The polymerase adds nucleotides to growing polynucleotides strands that are also attached to the solid substrate. Spatial control of polymerase activity is achieved by changing the rate of nucleotide polymerization at selected locations on the surface of the solid substrate. The rate of polymerization is changed by inhibiting or promoting activity of the polymerase. In some implementations, activation of electrodes in the microelectrode array changes the rate of nucleotide polymerization. Nucleotides are added to the growing polynucleotide strands at areas where the polymerase is active. By varying the locations where the substrate-bound polymerase is active and the species of nucleotide added, a population of polynucleotides with different, arbitrary sequences is synthesized on the surface of the solid substrate.

Abstract: A universal template strand built with universal base analogs is used as a template for polynucleotide synthesis. The universal template strand can hybridize to any sequence of nucleotides. A new polynucleotide is synthesized by using a polymerase to extend a primer hybridized to the universal template strand. Unlike primer extension in polymerase chain reactions, base pairing with nucleotides in the template strand does not specify the sequence of the new polynucleotide. Instead, the sequence of the new polynucleotide is specified by the order of addition of protected nucleotides. After addition of a single species of protected nucleotide, the blocking group is removed and another protected nucleotide is added. The order of nucleotide addition can be varied to create any sequence. After synthesis, the polynucleotide can be dehybridized from the universal template strand. The universal template strand may then be reused to synthesize a different polynucleotide.

Abstract: This disclosure describes a technique for performing random access in a pool of polynucleotides by using one unique primer and one homopolymer primer to selectively amplify some but not all of the polynucleotides in the pool. The polynucleotides are synthesized by a template independent polymerase such as terminal deoxynucleotide transferase (TdT) rather than by phosphoramidite synthesis. Enzymatic synthesis efficiently creates homopolymer sequences through unregulated synthesis. Use of one homopolymer primer instead of two unique primers decreases the complexity, time, and cost of synthesizing the polynucleotides. Use of a unique primer provides a sequence that can be varied to uniquely identify multiple different groups of polynucleotides. This enables random access by polymerase chain reaction (PCR) amplification while still benefitting from the efficiency of homopolymer synthesis. The polynucleotides may include payload regions that use a sequence of nucleotides to encode digital data.

Abstract: This disclosure provides electrochemically-cleavable linkers with cleavage potentials that are less than the redox potential of the solvent in which the linkers are used. In some applications, the solvent may be water or an aqueous buffer solution. The linkers may be used to link a nucleotide to a bound group. The linkers include a cleavable group which may be one of a methoxybenzyl alcohol, an ester, a propargyl thioether, or a trichloroethyl ether. The linkers may be cleaved in solvent by generating an electrode potential that is less than the redox potential of the solvent. In some implementations, an electrode array may be used to generate localized electrode potentials which selectively cleave linkers bound to the activated electrode. Uses for the linkers include attachment of blocking groups to nucleotides in enzymatic oligonucleotide synthesis.