Long-read Sequencing Dna
Long-read Sequencing Dna - Related Videos
08:57
Amplicon Sequencing using the Long-Read Sequencing Technologies
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2025
This protocol was optimized for targeted deep sequencing of 18 drug-resistance regions in Mycobacterium tuberculosis using a long-read sequencing platform, followed by analysis with a tuberculosis-specific bioinformatics pipeline designed for long-read data.
06:56
Purification of High Molecular Weight Genomic DNA from Powdery Mildew for Long-Read Sequencing
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Cited by 17 •
2017
Described here is a method for the extraction, purification, and quality control of genomic DNA from the obligate biotrophic fungal pathogen, powdery mildew, for use in long-read genome sequencing.
10:34
Ultra-long Read Sequencing for Whole Genomic DNA Analysis
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Cited by 28 •
2019
Long-read sequences greatly facilitate the assembly of complex genomes and characterization of structural variation. We describe a method to generate ultra-long sequences by nanopore-based sequencing platforms. The approach adopts an optimized DNA extraction followed by modified library preparations to generate hundreds of kilobase reads with moderate coverage from human cells.
08:38
Targeted DNA Methylation Analysis by Next-generation Sequencing
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Cited by 83 •
2015
Bisulfite amplicon sequencing (BSAS) is a method for quantifying cytosine methylation in targeted genomic regions of interest. This method uses bisulfite conversion paired with PCR amplification of target regions prior to next-generation sequencing to produce absolute quantitation of DNA methylation at a base-specific level.
09:31
Amplification, Next-generation Sequencing, and Genomic DNA Mapping of Retroviral Integration Sites
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Cited by 56 •
2016
We describe a protocol for amplifying retroviral integration sites from the genomic DNA of infected cells, sequencing the amplified virus-host junctions, and then mapping these sequences to a reference genome. We also describe techniques to quantify the distribution of integration sites relative to various genomic annotations using BEDTools.
FAQs
The instrument detects a signal produced as each DNA molecule is read continuously. In nanopore sequencing, DNA passage changes electrical current, whereas fluorescence can indicate nucleotide incorporation. These signals are interpreted to determine nucleotide order. Continuous measurement preserves relationships among bases across long molecules, supporting analysis of regions that are difficult to reconstruct from separated sequence fragments.
Extended reads can pass through repeated elements and connect them with neighboring unique sequences. That continuity helps distinguish where repeated segments belong and reveals larger rearrangements in their genomic context. As a result, researchers can improve genome completeness and examine structural features that short-read approaches may not resolve reliably.
A long molecule can carry multiple nearby sequence features on the same physical DNA strand, helping researchers determine which variants occur together on a haplotype. The same continuity supports recognition of structural variants and repeat expansions. This context can make genetic findings easier to interpret than when evidence comes from separately observed short fragments.
They provide two different measurement strategies for observing nucleotide order. Nanopore systems infer sequence from changes in electrical current as DNA passes through a pore, while fluorescence-based systems detect signals associated with nucleotide incorporation. The underlying signal type differs, but both approaches generate extended reads that can be used for genomic reconstruction and variant analysis.
The workflow begins with individual DNA molecules entering a sequencing system that records either electrical-current changes or fluorescence during reading. Those measurements are converted into nucleotide sequences, producing reads that may span thousands of bases. Researchers then use the resulting data for tasks such as de novo genome assembly, structural-variant detection, repeat-expansion analysis, or haplotype resolution.
It is particularly useful when a genome contains repetitive or structurally complex regions that are difficult to place using short reads. Long molecules can connect sequence across these regions, supporting de novo assembly, which constructs a genome without relying on an established reference. The resulting assemblies can improve genome completeness and reveal previously unresolved structure.
The method can expose structural variants, repeat expansions, and haplotype relationships that contribute to how genetic differences are interpreted. It also supports full-length transcript characterization, adding information about complete transcript structures. Together, these outputs help investigate disease mechanisms, compare genome organization during evolution, and strengthen the genetic evidence used in personalized medicine.