Long-Read Sequencing Technology

Illumina synthetic long-read sequencing technology is a highly accurate, end-to-end solution that can be used to:

  • Generate synthetic long reads for de novo assembly and genome finishing applications
  • Sequence traditionally challenging genomes, such as those containing stretches of highly repetitive elements
  • Perform whole human genome phasing to identify co-inherited alleles, haplotype information, and phase de novo mutations

End-to-end solution for long reads or whole human genome phasing

Moleculo, acquired by Illumina in late 2012, developed an innovative technology for generating long reads that combines a new library prep method and genome analysis tools. The technology breaks DNA into large fragments that are sequenced on standard Illumina sequencing platforms for subsequent assembly into synthetic long reads or whole human genome phasing using proprietary informatics.

TruSeq Synthetic Long-Read DNA Library Prep is a complete end-to-end workflow that encompasses library preparation, sequencing, and informatics. Applications for this long-read technology include genome finishing, de novo assembly, metagenomics, and whole human genome phasing.

Reconstructs fragments into long read data

The TruSeq Synthetic Long-Read technology begins by fragmenting genomic DNA to approximately 10 kilobases. Next, these fragments are clonally amplified, sheared, and marked with a unique barcode. They are then sequenced with Illumina technology.

The short sequence reads originating from each molecule are assembled into synthetic long-reads, or long fragments. These fragments assign haplotype information to homologous chromosomes in the phasing application. The fragments are also used for genome finishing or de novo sequencing in the long reads application.

Better genome sequencing and human phasing

Synthetic long-read sequencing technology has the potential to improve the efficiency and accuracy of many existing DNA sequencing applications while increasing the coverage of clinically important genes. These advantages allow for the phased re‐sequencing of human genomes and rapid de novo sequencing of plant and animal genomes.

The long reads produced typically span more than one heterozygous SNP in the phasing application. A proprietary phasing algorithm "stitches" multiple long reads into a single haplotype and thus phases the genome.

The technology simplifies de novo sequencing because large repeat regions in the DNA fragments can easily be spanned.

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