In this AGBT presentation, Marty Badgett shares a look at the latest results from circular consensus sequencing (CCS) mode for highly accurate reads and data from our soon-to-be-released Sequel II System. As he demonstrates, CCS reads cover the same molecule many times, delivering high consensus accuracy despite noisy raw reads; on average, reaching 10 passes achieves Q30 accuracy. Badgett offers several examples where this is useful, such as pharmacogenomic gene analysis and resolving metagenomic communities. He also provides an update on the Iso-Seq method, which can now segregate transcripts into haplotype-specific alleles using a new tool called Iso-Phase.
In this AGBT presentation, Mike Hunkapiller shares insights on using highly accurate long (HiFi) reads generated in circular consensus sequencing (CCS) mode for comprehensive genomic analysis and provides examples such as the sequencing of a Genome in a Bottle reference sample, which concluded with Q48 accuracy, 18 Mb contigs, and clearly phased haplotypes.
In this AGBT presentation from AGBT 2019, Jason Underwood, shares information about single-cell isoform sequencing (scIso-Seq), focusing on a collaborative project with the labs of Evan Eichler and Alex Pollen. For this effort, scientists used Drop-seq sample prep and then loaded cDNA products onto the Sequel System. Results from a barnyard experiment using mouse and human cells as well as from cerebral organoids demonstrated that this approach could deliver cell type-specific gene expression data. Underwood also presents data from the Sequel II System comparing chimp and human organoids, resulting in information about 14,000 unique genes with important insights for post-transcriptional…
At AGBT 2020, Adam Ameur from Uppsala University discussed the use of long-read PacBio sequencing to detect off-target results from CRISPR/Cas9 gene editing studies. His team uses HiFi reads from the Sequel II System to perform whole genome sequencing and figure out exactly where guide RNAs bind. In one example using a human embryonic kidney cell line, they found 55 off-target sites for three guide RNAs. Ameur’s group has already generated preliminary data on results from editing living cells.
Tina Graves-Lindsay from the McDonnell Genome Institute reports at AGBT 2020 on how her team is using PacBio sequencing to produce reference-grade human genome assemblies. With highly accurate HiFi reads, no error correction step is needed during the sequencing and analysis process, and they can produce reference-grade assemblies with half the sequence coverage needed before. They are now generating diploid assemblies and will be contributing to the human pangenome reference project.
In a push to develop insect-based food sources for people, Brenda Oppert from the USDA has been sequencing bug genomes with PacBio technology. Long reads are essential because of the highly repetitive sequences and large genomes. On the Sequel II System, a single SMRT Cell is sufficient to generate 350-fold coverage and produce a high-quality assembly for some of the insects she’s studying.