Summary
Nanopore and PacBio technologies read tens of thousands of bases at once, resolving repeats and structural variants.
In depth
PacBio HiFi gives accurate reads of 10 to 20 kb; Oxford Nanopore reads can exceed a megabase, and can detect base modifications directly. They resolve repeats and structural variants and allowed gapless T2T assembly.
Long reads span repetitive regions and detect structural variants and haplotypes. Higher raw error rates are reduced by consensus or improved chemistry. Direct RNA sequencing reads native RNA with modifications.
Key idea: reads long enough to span a repeat make assembly far easier.
Long-read technologies read single DNA molecules of tens of thousands to millions of bases. PacBio HiFi reads circular molecules repeatedly for high accuracy, while Oxford Nanopore threads DNA through a protein pore and detects changes in electrical current as each base passes.
Long reads span repeats, resolve structural variants, phase haplotypes and detect base modifications such as methylation directly. Nanopore devices are small and portable, used for real-time sequencing in outbreaks. Error rates, once high, have improved.
Example: telomere-to-telomere genome assembly used long reads to fill gaps.
Frequently asked questions
What is Long-Read Sequencing?
Nanopore and PacBio technologies read tens of thousands of bases at once, resolving repeats and structural variants.
Which area of biology covers Long-Read Sequencing, and how advanced is it?
Long-Read Sequencing is one of the 56 topics in Biotechnology & Genomics. It is rated Advanced, so it suits learners who want specialist depth. Related topics in this area include DNA Sequencing, Next-Generation Sequencing, Genome Assembly.
Why does Long-Read Sequencing matter?
It complements short reads, giving a more complete picture of genomes.
Can you give an example of Long-Read Sequencing?
Portable MinION devices sequence Ebola in the field.
What should I learn before Long-Read Sequencing?
Work through the Beginner topics in Biotechnology & Genomics first, such as Biotechnology, Genetic Engineering, Selective Breeding, then return to Long-Read Sequencing. Advanced topics assume the Intermediate vocabulary.
What topics are related to Long-Read Sequencing?
The closest topics to Long-Read Sequencing are DNA Sequencing, Next-Generation Sequencing, Genome Assembly, Genomics. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Long-Read Sequencing?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Long-Read Sequencing. To practise the whole of Biotechnology & Genomics, use the Biotechnology & Genomics quiz.
How is Long-Read Sequencing different from DNA Sequencing?
Long-Read Sequencing: Nanopore and PacBio technologies read tens of thousands of bases at once, resolving repeats and structural variants. DNA Sequencing: Determining the order of bases, from Sanger chain termination to modern high-throughput methods. Read both side by side and note what each one explains.
How should I study Long-Read Sequencing step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with DNA Sequencing and explain the difference aloud. Finally, take the Biotechnology & Genomics quiz and come back to this page for any question you miss.