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.

The present invention relates to a device (100) and a method for optically controlling a chemical reaction in a reaction chamber (149) comprising a reagent fluid (114). In a preferred embodiment, the chemical reaction comprises a nucleic acid sequencing on a wiregrid. Based on strong optical confinement of excitation light (110) and of cleavage light (112), the sequencing reaction can be read-out. Stepwise sequencing is achieved by using nucleotides with optically cleavable blocking moieties. After read-out the built in nucleotide is deblocked by cleavage light through the same substrate. This ensures that only bound nucleotides will be unblocked. In order to avoid overheating by cleavage light, the reagent fluid is circulated along the surface of the substrate (101).

Provided are methods of producing size-selected nucleic acid libraries. The methods include contacting a nucleic acid sample and a nucleic acid binding reagent including an affinity tag, under conditions in which nucleic acids of less than a desired length are substantially bound to the nucleic acid binding reagent and nucleic acids of the desired length are substantially not bound to the nucleic acid binding reagent. The conditions include the duration of the contacting, the concentration of the nucleic acid binding reagent, or both. The methods further include separating, using the affinity tag, the nucleic acids of less than the desired length bound to the nucleic acid binding reagent from the nucleic acids of the desired length not bound to the nucleic acid binding reagent, to produce a size-selected nucleic acid library. Compositions and kits that find use, e.g., in practicing the methods of the present disclosure, are also provided.

The present invention provides improved automated systems and methods for synthesis of biopolymers including DNA and RNA. The automated systems and methods represent a number of improvements over existing systems for multiplex synthesis of biopolymers in a combinatorial fashion.

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 for synthesizing nucleic acids and a method for synthesizing nucleic acids using the same. The apparatus includes a first substrate including a surface on which the nucleic acids are synthesized, a second substrate including a deprotection solution, a transporter configured to move the first substrate or the second substrate, and a transporter controller in operable communication with the transporter.