Defined sequence RNA synthesis by 3′.fwdarw.5′ direction is now well established and currently in use for synthesis and development of vast variety of therapeutic grade RNA and Si RNA etc. A number of such synthetic RNA requires a modification or labeling of 3′-end of an oligonucleotide. The synthesis of 3′-end modified RNA requiring lipophilic, long chain ligands or chromophores, using 3′.fwdarw.5′ synthesis methodology is challenging, requires corresponding solid support and generally results in low coupling efficiency and lower purity of the final oligonucleotide in general because of large amount of truncated sequences containing desired hydrophobic modification. We have approached this problem by developing reverse RNA monomer phosphoramidites for RNA synthesis in 5′.fwdarw.3′-direction. They lead to very clean oligonucleotide synthesis allowing for introduction of various modifications at the 3′-end.

Selectively controllable cleavable linkers include electrochemically-cleavable linkers, photolabile linkers, thermolabile linkers, chemically-labile linkers, and enzymatically-cleavable linkers. Selective cleavage of individual linkers may be controlled by changing local conditions. Local conditions may be changed by activating electrodes in proximity to the linkers, exposing the linkers to light, heating the linkers, or applying chemicals. Selective cleaving of enzymatically-cleavable linkers may be controlled by designing the sequences of different sets of the individual linkers to respond to different enzymes. Cleavable linkers may be used to attach polymers to a solid substrate. Selective cleavage of the linkers enables release of specific polymers from the solid substrate. Cleavable linkers may also be used to attach protecting groups to the ends of growing polymers. The protecting groups may be selectively removed by cleavage of the linkers to enable growth of specific polymers.

Disclosed herein include methods, devices, kits, and systems for nucleic acid sequencing, for example, to determine cell-cell interaction using a dielectrophoresis microfluidic device.

A method for forming discrete volumes of aqueous fluid may comprise flowing aqueous fluid into a first conduit from a supply of aqueous fluid and flowing into the first conduit a spacing liquid supplied from a second conduit, the spacing liquid being immiscible with the aqueous fluid. The flowing of the aqueous fluid and the spacing liquid into the first conduit forms discrete volumes of the aqueous fluid, with consecutive discrete volumes of the aqueous fluid separated by the spacing liquid. The method may further comprise transferring the discrete volumes of the aqueous fluid and spacing liquid from the first conduit to a third conduit for processing.

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.

The present disclosure provides biochips and methods for making biochips. A biochip can comprise a nanopore in a membrane (e.g., lipid bilayer) adjacent or in proximity to an electrode. Methods are described for forming the membrane and inserting the nanopore into the membrane. The biochips and methods can be used for nucleic acid (e.g., DNA) sequencing. The present disclosure also describes methods for detecting, sorting, and binning molecules (e.g., proteins) using biochips.

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.

A method including (a) providing an amplification reagent including an array of sites, and a solution having different target nucleic acids; and (b) reacting the amplification reagent to produce amplification sites each having a clonal population of amplicons from a target nucleic acid from the solution. The reacting can include simultaneously transporting the nucleic acids to the sites at an average transport rate, and amplifying the nucleic acids that transport to the sites at an average amplification rate, wherein the average amplification rate exceeds the average transport rate. The reacting can include producing a first amplicon from a nucleic acid that transports to each of the sites, and producing subsequent amplicons from the nucleic acid or from the first amplicon, wherein the average rate at which the subsequent amplicons are generated exceeds the average rate at which the first amplicon is generated.

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.

The present disclosure provides biochips and methods for making biochips. A biochip can comprise a nanopore in a membrane (e.g., lipid bilayer) adjacent or in proximity to an electrode. Methods are described for forming the membrane and insert-ing the nanopore into the membrane. The biochips and methods can be used for nucleic acid (e.g., DNA) sequencing. The present disclosure also describes methods for detecting, sorting, and binning molecules (e.g., proteins) using biochips.