Single Molecule, Real-Time (SMRT) Sequencing uses the natural process of DNA replication to sequence long fragments of native DNA. As such, starting with high-quality, high molecular weight (HMW) genomic DNA (gDNA) will result in better sequencing performance across difficult to sequence regions of the genome. To obtain the highest quality, long DNA it is important to start with sample types compatible with HMW DNA extraction methods. This technical note is intended to give general guidance on sample collection, preparation, and storage across a range of commonly encountered sample types used for SMRT Sequencing whole genome projects. It is important to…
Single Molecule, Real-Time (SMRT) Sequencing uses the natural process of DNA replication to sequence long fragments of native DNA in order to produce highly accurate long reads, or HiFi reads. As such, starting with high-quality, high molecular weight (HMW) genomic DNA (gDNA) will result in longer libraries and better performance during sequencing. This technical note is intended to give recommendations, tips and tricks for the extraction of DNA, as well as assessing and preserving the quality and size of your DNA sample to be used for HiFi sequencing.
The Agilent 5200, 5300, and 5400 Fragment Analyzer instruments are fast, high-resolution benchtop capillary electrophoresis (CE) platforms that utilize proprietary markers to accurately size fragments ranging from 10 to 50 kb. This platform allows important DNA quality checkpoints to be completed in one hour for de novo large-genome sequencing projects and other PacBio applications leveraging multi-kilobase read lengths. The instrument can be used in place of time-consuming QC steps involving pulsed field gel electrophoresis (PFGE), saving time by avoiding multiple overnight gel runs when preparing large-insert SMRTbell libraries. Alternative DNA-sizing instruments cannot accurately resolve large DNA fragments in this range.
The SMRTbell Express Template Prep Kit 2.0 provides a streamlined, single-tube reaction strategy to generate SMRTbell libraries from 500 bp to >50 kb insert size targets to support large-insert genomic libraries, multiplexed microbial genomes and amplicon sequencing. With this new formulation, we have increased both the yield and efficiency of SMRTbell library preparation for SMRT Sequencing while further minimizing handling-induced DNA damage to retain the integrity of genomic DNA (gDNA). This product note highlights the key benefits, performance, and resources available for supporting de novo genome sequencing and structural variant detection projects. Our large-insert gDNA protocol has been streamlined to…
The Agilent Femto Pulse system automated pulsed-field CE instrument is a fast, high-resolution benchtop capillary electrophoresis (CE) platform that utilizes pulsed-field electrophoresis to separate high molecular weight DNA fragments. This platform allows important DNA quality checkpoints to be completed in less than 1.5 hours with minimal sample input for de novo large genome sequencing projects and other PacBio applications leveraging multi-kilobase read lengths. The instrument can be used in place of gel-based pulsed-field electrophoresis (PFGE) systems to fully support generation of large-insert SMRTbell libraries with accurate sizing to 165 kb. Alternative DNA sizing instruments cannot accurately resolve large DNA fragments…
The SMRTbell Express Template Prep Kit 2.0 provides a streamlined, single-tube reaction strategy to generate SMRTbell libraries from 500 bp to >50 kb insert size targets to support large-insert genomic libraries, multiplexed microbial genomes and amplicon sequencing. With this new formulation, we have increased both the yield and efficiency of SMRTbell library preparation for SMRT Sequencing while further minimizing handling-induced DNA damage to retain the integrity of genomic DNA (gDNA). This product note highlights the key benefits, performance, and resources available for obtaining complete microbial genome assemblies with multiplexed sequencing. By using a single-tube, addition-only strategy, the streamlined workflow reduces…
As the foundation for scientific discoveries in genetic diversity, sequencing data must be accurate and complete. With highly accurate long-read sequencing, or HiFi sequencing, there is no longer a compromise between read length and accuracy. HiFi sequencing enables some of the highest quality de novo genome assemblies available today as well as comprehensive variant detection in human samples. PacBio HiFi libraries constructed using our standard library workflows require at least 3 µg of DNA input per 1 Gb of genome length, or ~10 µg for a human sample. For some samples it is not possible to extract this amount of…
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.
Single-Molecule Real-Time (SMRT) DNA sequencing is unique in that nucleotide incorporation events are monitored in real time, leading to a wealth of kinetic information in addition to the extraction of the primary DNA sequence. The dynamics of the DNA polymerase that is observed adds an additional dimension of sequence-dependent information, and can be used to learn more about the molecule under study. First, the primary sequence itself can be determined more accurately. The kinetic data can be used to corroborate or overturn consensus calls and even enable calling bases in problematic sequence contexts. Second, using the kinetic information, we can…
DNA is under constant stress from both endogenous and exogenous sources. DNA base modifications resulting from various types of DNA damage are wide-spread and play important roles in affecting physiological states and disease phenotypes. Examples include oxidative damage (8- oxoguanine, 8-oxoadenine; aging, Alzheimer’s, Parkinson’s), alkylation (1-methyladenine, 6-O- methylguanine; cancer), adduct formation (benzo[a]pyrene diol epoxide (BPDE), pyrimidine dimers; smoking, industrial chemical exposure, chemical UV light exposure, cancer), and ionizing radiation damage (5-hydroxycytosine, 5- hydroxyuracil, 5-hydroxymethyluracil; cancer). Currently, these and other products of DNA damage cannot be sequenced with existing sequencing methods. In contrast, single molecule, real-time (SMRT) DNA sequencing can report…
Maximizing the read length of next generation sequencing (NGS) facilitates de novo genome assembly. Currently, the PacBio RS II system leads the industry with respect to maximum possible NGS read lengths. Amplicon Express specializes in preparation of high molecular weight, NGS-grade genomic DNA for a variety of applications, including next generation sequencing. This study was performed to evaluate the effects of gDNA quality on PacBio RS II read length.
Recent advances in next-generation sequencing have led to an increased use of formalin-fixed and paraffin-embedded (FFPE) tissues for medical samples in disease and scientific research. Single Molecule, Real-Time (SMRT) Sequencing offers a unique advantage for direct analysis of FFPE samples without amplification. However, obtaining ample long-read information from FFPE samples has been a challenge due to the quality and quantity of the extracted DNA. FFPE samples often contain damaged sites, including breaks in the backbone and missing or altered nucleotide bases, which directly impact sequencing and target enrichment. Additionally, the quality and quantity of the recovered DNA vary depending on…
Aim: The vast majority of donor typing relies on sequencing exons 2 and 3 of HLA class I genes (HLA-A, -B, -C). With such an approach certain allele combinations do not result in the anticipated “high resolution” (G-code) typing, due to the lack of exon-phasing information. To resolve ambiguous typing results for a haplotype frequency project, we established a whole gene sequencing approach for HLA class I, facilitating also an estimation of the degree of sequence variability outside the commonly sequenced exons. Methods: Primers were developed flanking the UTR regions resulting in similar amplicon lengths of 4.2-4.4 kb. Using a…
Aim: In contrast to exon-based HLA-typing approaches, whole gene genotyping crucially depends on full-length sequences submitted to the IMGT/HLA Database. Currently, full-length sequences are provided for only 7 out of 520 HLA-DPB1 alleles. Therefore, we developed a fully phased whole-gene sequencing approach for DPB1, to facilitate further exploration of the allelic structure at this locus. Methods: Primers were developed flanking the UTR-regions of DPB1 resulting in a 12 kb amplicon. Using a 4-primer approach, secondary primers containing barcodes were combined with the gene-specific primers to obtain barcoded full-gene amplicons in a single amplification step. Amplicons were pooled, purified, and ligated…
Single Molecule Real-Time (SMRT) Sequencing was used to generate long reads for whole genome shotgun sequencing of the genome of the`alala (Hawaiian crow). The ‘alala is endemic to Hawaii, and the only surviving lineage of the crow family, Corvidae, in the Hawaiian Islands. The population declined to less than 20 individuals in the 1990s, and today this charismatic species is extinct in the wild. Currently existing in only two captive breeding facilities, reintroduction of the ‘alala is scheduled to begin in the Fall of 2016. Reintroduction efforts will be assisted by information from the ‘alala genome generated and assembled by…