With Single Molecule, Real-Time (SMRT) Sequencing and the Sequel System, you can easily and cost effectively generate highly accurate long reads (HiFi reads, >99% single-molecule accuracy) from genes or regions of interest ranging in size from several hundred base pairs to 20 kb. Target all types of variation across relevant genomic regions, including low complexity regions like repeat expansions, promoters, and flanking regions of transposable elements.
In this webinar, Sarah Kingan, Staff Scientist, PacBio, presents recent work on de novo genome assembly using PacBio HiFi reads. She highlights the benefits of HiFi data for base level accuracy, haplotype phasing, and ease of computation. And in samples ranging from human to plants, she benchmarks various tools for HiFi assembly and phasing, including the newly extended FALCON-Unzip assembler. Subsequently, Andrew Carroll, Genomics Product Lead, GoogleAI, explores how the GoogleAI team retrained DeepVariant, a highly accurate SNP and Indel caller, for PacBio HiFi data. The resulting DeepVariant models achieve comparable accuracies to short-read methods with the additional benefit of…
Single cell RNA-seq (scRNA-seq) is an emerging field for characterizing cell heterogeneity in complex tissues. However, most scRNA-seq methodologies are limited to gene count information due to short read lengths. Here, we combine the microfluidics scRNA-seq technique, Drop-Seq, with PacBio Single Molecule, Real-Time (SMRT) Sequencing to generate full-length transcript isoforms that can be confidently assigned to individual cells. We generated single cell Iso-Seq (scIso-Seq) libraries for chimp and human cerebral organoid samples on the Dolomite Nadia platform and sequenced each library with two SMRT Cells 8M on the PacBio Sequel II System. We developed a bioinformatics pipeline to identify, classify,…
With Single Molecule, Real-Time (SMRT) Sequencing and the Sequel Systems, you can easily and affordably sequence complete transcript isoforms in genes of interest or across the entire transcriptome. The Iso-Seq method allows users to generate full-length cDNA sequences up to 10 kb in length — with no assembly required — to confidently characterize full-length transcript isoforms.
Leaky gut, or intestinal barrier immaturity with elevated intestinal permeability, is the proximate cause of susceptibility to necrotizing enterocolitis in preterm neonates. We recently revealed intestinal barrier maturation was associated with exclusive breastfeeding, less antibiotic exposure, most importantly, altered composition of the gut microbiota. However, sequencing short regions of 16S rRNA gene amplicon failed to identify the specific bacterial groups associated with improved or aberrant intestinal permeability. In this study, we performed high-throughput amplicon sequencing of the full length 16S rRNA gene with single-nucleotide resolution for a cohort of 66 preterm neonates born at 24-33 weeks of gestation who had…
Background: Long-read sequencing presents several potential advantages for providing more complete gene profiling of metagenomic samples. Long reads can capture multiple genes in a single read, and longer reads typically result in assemblies with better contiguity, especially for higher abundance organisms. However, a major challenge with using long reads has been the higher cost per base, which may lead to insufficient coverage of low-abundance species. Additionally, lower single-pass accuracy can make gene discovery for low-abundance organisms difficult. Methods: To evaluate the pros and cons of long reads for metagenomics, we directly compared PacBio and Illumina sequencing on a soil-derived sample,…
In this webinar, Sarah Kingan, Staff Scientist, PacBio, and Kevin McKernan, Founder and Chief Science Officer, Medicinal Genomics, describe their work assembling the most comprehensive and complete cannabis genome of a Type II (THCA and CBDA producing) plant. They also share the latest advances in cannabis genomics, including how PacBio long-read sequencing enables high-quality genomics research in plants, annotation of the cannabis reference genome using full-length transcript sequencing, and new insights into cannabinoid synthesis across different types of cannabis plants.
Introduction: Long-read sequencing has been applied successfully to assemble genomes and detect structural variants. However, due to high raw-read error rates (10-15%), it has remained difficult to call small variants from long reads. Recent improvements in library preparation and sequencing chemistry have increased length, accuracy, and throughput of PacBio circular consensus sequencing (CCS) reads, resulting in 10-20kb reads with average read quality above 99%. Materials and Methods: We sequenced a 12kb library from human reference sample HG002 to 18-fold coverage on the PacBio Sequel II System with three SMRT Cells 8M. The CCS algorithm was used to generate highly-accurate (average…
Genomic regions with extreme base composition bias and repetitive sequences have long proven challenging for targeted enrichment methods, as they rely upon some form of amplification. Similarly, most DNA sequencing technologies struggle to faithfully sequence regions of low complexity. This has especially been trying for repeat expansion disorders such as Fragile X disease, Huntington disease and various Ataxias, where the repetitive elements range from several hundreds of bases to tens of kilobases.
Discover how the CRISPR-Cas9 system and PacBio long-read sequencing enable targeting of previously unsequencable regions of the genome, including long repeat expansions.
In this webinar, Jonas Korlach, Chief Scientific Officer, PacBio provides an overview of the features and the advantages of the new Sequel II System. Kiran Garimella, Senior Computational Scientist, Broad Institute of MIT and Harvard University, describes his work sequencing humans with HiFi reads enabling discovery of structural variants undetectable in short reads. Luke Tallon, Scientific Director, Genomics Resource Center, Institute for Genome Sciences, University of Maryland School of Medicine, covers the GRC’s work on bacterial multiplexing, 16S microbiome profiling, and shotgun metagenomics. Finally, Shane McCarthy, Senior Research Associate, University of Cambridge, focuses on the scaling and affordability of high-quality…
Genomics studies have shown that the insertions, deletions, duplications, translocations, inversions, and tandem repeat expansions in the structural variant (SV) size range (>50 bp) contribute to the evolution of traits and often have significant associations with agronomically important phenotypes. However, most SVs are too small to detect with array comparative genomic hybridization and too large to reliably discover with short-read DNA sequencing. While de novo assembly is the most comprehensive way to identify variants in a genome, recent studies in human genomes show that PacBio SMRT Sequencing sensitively detects structural variants at low coverage. Here we present SV characterization in…
The ability to identify and understand the functions of the complex microbial populations living in, on, and around us requires comprehensive characterization of each community member. Highly accurate long reads– HiFi reads–with single-molecule resolution make Single Molecule, Real-Time (SMRT) Sequencing ideal for full-length 16S rRNA sequencing, long-read metagenomic profiling, and shotgun metagenomic assembly.