There is disclosed an electrode array device having an adsorbed porous reaction layer for improved synthesis quality. The array comprises a plurality of electrodes on a substrate, wherein the electrodes are electronically connected to a computer control system. The array has an adsorbed porous reaction layer on the plurality of electrodes, wherein the adsorbed porous reaction layer comprises a chemical species having at least one hydroxyl group. In the preferred embodiment, the reaction layer is sucrose. A method for preparing an electrode array for improved synthesis quality is disclosed. The method comprises a cleaning method and a method of attachment of a reaction layer. The cleaning method comprises a plasma cleaning method and a chemical cleaning method. The reaction layer is attached after cleaning by exposing the microarray to a solution containing the chemical species having at least one hydroxyl group.

Systems and methods for polynucleotide synthesis utilize electrochemical deprotection and novel redox chemistries compatible with advanced CMOS nodes, for highly reliable and massively scalable parallel construction of polynucleotide segments having a desired sequence or sequences. Via use of these exemplary techniques, low-cost and large-scale polynucleotide synthesis is facilitated, for example for data storage and retrieval applications.

A system may include a first conduit configured to form a first batch of discrete volumes of aqueous fluid separated by spacing liquid disposed between consecutive volumes of aqueous fluid, the spacing liquid being immiscible with the aqueous fluid volumes; a second conduit, fluidically coupled to the first conduit, the second conduit configured to statically hold the first batch of discrete volumes of aqueous fluid; and a third conduit configured to receive the first batch of discrete volumes of aqueous fluid from the second conduit. The third conduit can be configured to transfer the discrete volumes of aqueous fluid of the first batch for downstream processing.

A method for DNA synthesis using protected nucleosides is disclosed. The nucleosides may be nucleoside triphosphates or nucleoside phosphoramidites with nucleobases attached to electrochemically-cleavable linkers. Removal of a protecting group by application of a voltage in solution triggers a cyclization reaction that cleaves the electrochemically-cleavable linkers. The electrochemically-cleavable linkers may include an amide linkage and an amide that forms a lactam or an ester linkage and a protected alcohol that forms a lactone when the protecting group is removed. The voltage used to cleave the electrochemically-cleavable linkers may be generated by activation of individual electrodes on a microelectrode array. The microelectrode array can be a substrate for solid-phase synthesis of oligonucleotides. Activation of specific electrodes removes the protecting groups at those electrodes and thus enables spatially-controlled extension of the oligonucleotides. Protected nucleosides linked to protecting groups by electrochemically-cleavable linkers are also disclosed.

An apparatus includes a flow cell body, a plurality of electrodes, an integrated circuit, and an imaging assembly. The flow cell body defines one or more flow channels and a plurality of wells. Each flow channel is configured to receive a flow of fluid. Each well is fluidically coupled with the corresponding flow channel. Each well is configured to contain at least one polynucleotide. Each electrode is positioned in a corresponding well of the plurality of wells. The electrodes are operable to effect writing of polynucleotides in the corresponding wells. The integrated circuit is operable to drive selective deposition or activation of selected nucleotides to attach to polynucleotides in the wells to thereby generate polynucleotides representing machine-written data in the wells. The imaging assembly is operable to capture images indicative of one or more nucleotides in a polynucleotide.

There is disclosed an electrode array architecture employing continuous and discontinuous circumferential electrodes. There is further disclosed a process for the neutralization of acid generated at anode(s) by base generated at cathode(s) circumferentially located to each other so as to confine a region of pH change. The cathodes can be displayed as concentric rings (continuous) or as counter electrodes in a cross pattern (discontinuous). In this way reagents, such as acid, generated in a center electrode are countered (neutralized) by reagents, such as base, generated at the corners or at the outer ring.

An apparatus includes a flow cell body, a plurality of electrodes, an integrated circuit, and an imaging assembly. The flow cell body defines one or more flow channels and a plurality of wells. Each flow channel is configured to receive a flow of fluid. Each well is fluidically coupled with the corresponding flow channel. Each well is configured to contain at least one polynucleotide. Each electrode is positioned in a corresponding well of the plurality of wells. The electrodes are operable to effect writing of polynucleotides in the corresponding wells. The integrated circuit is operable to drive selective deposition or activation of selected nucleotides to attach to polynucleotides in the wells to thereby generate polynucleotides representing machine-written data in the wells. The imaging assembly is operable to capture images indicative of one or more nucleotides in a polynucleotide.

Systems and methods for polynucleotide synthesis utilize electrochemical deprotection and novel redox chemistries compatible with advanced CMOS nodes, for highly reliable and massively scalable parallel construction of polynucleotide segments having a desired sequence or sequences. Via use of these exemplary techniques, low-cost and large-scale polynucleotide synthesis is facilitated, for example for data storage and retrieval applications.

Various embodiments of the teachings relate to a system or method for sample preparation or analysis in biochemical or molecular biology procedures. The sample preparation can involve small volume processed in discrete portions or segments or slugs, herein referred to as discrete volumes. A molecular biology procedure can be nucleic acid analysis. Nucleic acid analysis can be an integrated DNA amplification/DNA sequencing procedure.

Polynucleotide synthesis performed with a substrate independent polymerase such as terminal deoxynucleotidyl transferase (TdT) is regulated by controlling the oxidation state of a metal cofactor. The oxidation state of the metal cofactor is changed to +2, thus activating the polymerase, by applying a voltage with electrodes or by introducing a chemical redox reagent. Addressable polynucleotide synthesis creates polynucleotides with different arbitrary sequences through use of spatial control of cofactor oxidation states to add nucleotides only at selected locations on an array. Control of metal oxidation states is regulated by selective activation of a microelectrode array, controlled addition of redox reagents to specific locations on the array, or controlled activation of photocatalysts at specific locations on the array. Scavengers in solution prevent cofactors distant from the selected locations from catalyzing polymerase activity and thereby maintain the localized effect of polymerase activation.