Long Fragment Read Whole Genome Sequencing

Long Fragment Read Whole Genome Sequencing Service Description

Current short-read based Whole Genome Sequencing (WGS) is the most widely used method for identifying genome-wide aberrations such as point mutations with read length typically less than several hundred base pairs. This short-read based WGS approach is proven to be highly informative in terms of detection of point mutations, indels and copy number alterations. However, short-read sequencing often results in sequences with scaffolding gaps, bias due to high GC content, repeat sequences and mis-aligned sequences. To interrogate the human genome at a higher resolution with better quality, the standard NGS workflow is challenged, especially for complex Structural Variation (SV) discovery, due to insufficient read coverage at breakpoints and loss of long-range genomic contiguity.

Technology

BGI’s innovative Single Tube Long Fragment Read (stLFR) technology produces reads longer than 10 kb with high consensus accuracy, uniform coverage and superior SV detection capability, while maintaining reproducibility and consistency. With a small amount of input HMW genomic DNA (as low as 1 ng, approximately 300 genomic equivalents), added to a single tube containing 30 million barcoded beads, where the gDNA molecules are barcoded and subjected to random priming and polymerase amplification. Co-barcoded DNA fragments are then released followed by a modified library preparation process. The resulting libraries undergo DNA Nanoball (DNB™) generation and DNBSEQ sequencing. BGI’s proprietary computational algorithm uses the barcodes to assemble sequencing reads to the original HMW DNA molecule, enabling the construction of contiguous segments of phased variants.

Long Fragment Read WGS for Superior SV Detection

Compared with conventional WGS services, stLFR-based Long Fragment Read WGS (lfrWGS) delivers less bias, higher cover- age, higher reproducibility and near-complete genomic information. It significantly improves structural variants detection while maintaining the same excellent sensitivity for SNP, Indel and CNV detection. lfrWGS does not have the high error rate problem and high cost of long read sequencing platforms from Pacific Biosciences and Oxford Nanopore but provides a means to detect many of the complex genomic variants including SV by computationally maintaining the genomic contiguity.

DNBSEQ™ Sequencing Technology

BGI Human Whole Genome Sequencing services are typically executed with our proprietary DNBSEQ™ NGS technology platform, for great sequencing data at the lowest cost in the industry.

DNBSEQ™ is BGI’s proprietary sequencing technology, developed by our Complete Genomics subsidiary in Silicon Valley. This system is powered by combinatorial Probe-Anchor Synthesis (cPAS), linear isothermal Rolling-Circle Replication and DNA Nanoballs (DNB™) technology, followed by high-resolution digital imaging.

Publications