bioRxiv Science⌕ Search

Biology subjects

Krajacich, B.

Publications and source records attributed to Krajacich, B..

2 recordsLinked to original sources

A simplified hybrid capture approach retains high specificity and enables PCR-free workflow

Hybrid capture is a critical technology for selective enrichment of genomic regions of interest, enabling cost-effective focused sequencing in both clinical and research applications. We present a simplified hybrid capture approach that eliminates complexities typically associated with hybridization-based selection methods by directly loading the hybridization product onto the sequencing flow cell. The workflow removes bead-based steps, washes, and post-hybridization PCR, while retaining high capture specificity and library complexity. The approach is enabled by the development of a streptavidin flow cell surface, a method to circularize and amplify captured targets on the flow cell, and a fast hybridization protocol. We demonstrate application across targeted panel sizes and improvements to library complexity and variant calling. We also show how the approach can be used to create an entirely PCR-free targeted sequencing workflow that further improves variant calling and enables the detection of repeat expansions.

genomics↗

FLEXIBLE, PRODUCTION-SCALE, HUMAN WHOLE GENOME SEQUENCING ON A BENCHTOP SEQUENCER

Human whole-genome sequencing (hWGS) provides comprehensive genomic information that can potentially help guide research in disease prevention and treatment and ultimately improve human health. Recent advancements in sequencing technology have improved sequencing quality and further reduced sequencing costs on bench-top sized instruments, making whole-genome sequencing an accessible technology for broader use. Here, we demonstrate the feasibility of a large whole genome sequencing project using a benchtop sequencer in a small laboratory setting, on a scale previously reserved for production-scale factory-sized machines. In this project, 807 samples were prepared and sequenced across 313 flow cells, with high sequencing quality at a median %Q30 of 96.6% and a median %Q40 of 89.31%. To screen library quality and maximize sample yield, we utilized 48-plex sample pre-pool QC runs to provide >1x coverage per sample prior to sample pooling and full-depth sequencing. With this strategy, we consistently achieved >30x human whole genome sequencing of three-plex sample trios with standard settings or up to 4 samples per run with a high-throughput run setting. Additionally, this low-pass data provided valuable sample-level insights, allowing for detection of chromosome copy number variations (CNV) prior to full-depth sequencing. With three instruments running concurrently, >2,800 30x human whole genomes could be sequenced per year. To further demonstrate additional flexibility present in the platform, we also explored two different use cases 1) large insert sizes (1kb+) library to achieve superior genome coverage; 2) a proof of concept for rapid WGS sequencing to minimize sample to answer turnaround time for time-critical sequencing applications. Sequencing of a 2x100 >30x human WGS can be achieved in <12 hours and subsequent generation of fastq, bam and vcf in <1 additional hour. This study provides a cost-effective and flexible real-world demonstration of achieving both high quality hWGS sequencing and instrument flexibility without the need for complex batching schemes or factory-sized sequencers.

molecular biology↗