The present invention generally relates to improved methods of assembly of two or more DNA fragments, methods of rapid ligation-independent cloning, and kits for rapid ligation-independent cloning and their uses.

The present invention relates to the analysis of complex single cell sequencing libraries. Disclosed are methods for enrichment of library members based on the presence of cell-of origin barcodes to identify and concentrate DNA that is relevant to interesting cells or components that would be expensive or difficult to study otherwise. Also, disclosed are methods of capturing cDNA library molecules by use of CRISPR systems, hybridization or PCR. The present invention allows for identifying the properties of rare cells in single cell RNA-seq data and accurately profile them through clustering approaches. Further information on transcript abundances from subpopulations of single cells can be analyzed at a lower sequencing effort. The methods also allow for linking TCR alpha and beta chains at the single cell level.

The invention comprises a method for determining a nucleotide sequence of a polynucleotide. In some embodiments, the method comprises providing a solid state substrate comprising a cis side and a trans side. The fluorescently labeled polynucleotide strand comprises (i) a proximal end that is attached to the carrier particle, (ii) a distal end that is cleavable by an exonuclease, and (iii) at least one fluorescently labeled nucleotide comprising a fluorescent label. The trans side of the substrate is illuminated with excitation light to create a fluorescence excitation zone. While the substrate is illuminated, the fluorescently labeled polynucleotide strand is reacted with an exonuclease so that mononucleotides are released serially from the distal end of the strand and diffuse through the fluorescence excitation zone, so that fluorescently labeled mononucleotides in the excitation zone emit fluorescent signals. The fluorescent signals are detected as a function of time, enabling the deduction of a polynucleotide sequence.

The present invention provides materials and methods useful for error correction of nucleic acid molecules. In one embodiment of the invention, a first plurality of double-stranded nucleic acid molecules having a nucleotide mismatch are fragmented by exposure to a molecule having unidirectional mismatch endonuclease activity. The nucleic acid molecules are cut at the mismatch site or near the mismatch site, leaving a double-stranded nucleic acid molecule having a mismatch at the end or near end of the molecule. The nucleic acid molecule is then exposed to a molecule having unidirectional exonuclease activity to remove the mismatched nucleotide. The missing nucleotides can then be filled in by the action of, e.g., a molecule having DNA polymerase activity. The result is double-stranded nucleic acid molecules with a decreased frequency of nucleotide mismatches. Also provided are novel nucleic acid sequences encoding mismatch endonucleases, polypeptides encoded thereby, as well as nucleic acid constructs, transgenic cells, and various compositions thereof.

The invention provides engineered meganucleases, derived from I-Crel, which have substitutions at particular positions that increase the activity of the nucleases for recognition sequences containing certain center sequences. The invention also provides methods of cleaving double-stranded DNA using such engineered meganucleases. The invention further provides methods for improving the activity of engineered meganucleases for recognition sequences containing certain center sequences.

The present invention relates to enzymes having DNA polymerase and 3′-5′ exonuclease activities. In particular, the present invention relates to a heat labile enzyme possessing a DNA polymerase II activity and a 3′-5′ exonuclease activity of marine origin. Furthermore, the present invention relates to a DNA polymerase primarily exerting a 3′-5′ activity, i.e. where the polymerase activity is absent. The present invention furthermore relates to the use of the exonuclease activity to degrade the 3′-5′ strand of double stranded DNA to perform single stranded overhang, e.g. in recombinant cloning processes, or in processes for removal of contaminating nucleic acid molecules.

The present invention relates to the analysis of complex single cell sequencing libraries. Disclosed are methods for enrichment of library members based on the presence of cell-of origin barcodes to identify and concentrate DNA that is relevant to interesting cells or components that would be expensive or difficult to study otherwise. Also, disclosed are methods of capturing cDNA library molecules by use of CRISPR systems, hybridization or PCR. The present invention allows for identifying the properties of rare cells in single cell RNA-seq data and accurately profile them through clustering approaches. Further information on transcript abundances from subpopulations of single cells can be analyzed at a lower sequencing effort. The methods also allow for linking TCR alpha and beta chains at the single cell level.

The present invention provides materials and methods useful for error correction of nucleic acid molecules. In one embodiment of the invention, a first plurality of double-stranded nucleic acid molecules having a nucleotide mismatch are fragmented by exposure to a molecule having unidirectional mismatch endonuclease activity. The nucleic acid molecules are cut at the mismatch site or near the mismatch site, leaving a double-stranded nucleic acid molecule having a mismatch at the end or near end of the molecule. The nucleic acid molecule is then exposed to a molecule having unidirectional exonuclease activity to remove the mismatched nucleotide. The missing nucleotides can then be filled in by the action of, e.g., a molecule having DNA polymerase activity. The result is double-stranded nucleic acid molecules with a decreased frequency of nucleotide mismatches. Also provided are novel nucleic acid sequences encoding mismatch endonucleases, polypeptides encoded thereby, as well as nucleic acid constructs, transgenic cells, and various compositions thereof.

The present invention provides materials and methods useful for error correction of nucleic acid molecules. In one embodiment of the invention, a first plurality of double-stranded nucleic acid molecules having a nucleotide mismatch are fragmented by exposure to a molecule having unidirectional mismatch endonuclease activity. The nucleic acid molecules are cut at the mismatch site or near the mismatch site, leaving a double-stranded nucleic acid molecule having a mismatch at the end or near end of the molecule. The nucleic acid molecule is then exposed to a molecule having unidirectional exonuclease activity to remove the mismatched nucleotide. The missing nucleotides can then be filled in by the action of, e.g., a molecule having DNA polymerase activity. The result is double-stranded nucleic acid molecules with a decreased frequency of nucleotide mismatches. Also provided are novel nucleic acid sequences encoding mismatch endonucleases, polypeptides encoded thereby, as well as nucleic acid constructs, transgenic cells, and various compositions thereof.

The present invention generally relates to improved methods of assembly of two or more DNA fragments, methods of rapid ligation-independent cloning, and kits for rapid ligation-independent cloning and their uses.