3.6 KiB
| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| DNA sequencer | 3/3 | https://en.wikipedia.org/wiki/DNA_sequencer | reference | science, encyclopedia | 2026-05-05T06:25:22.876127+00:00 | kb-cron |
=== Beckman Coulter === Beckman Coulter (now Danaher) has previously manufactured chain termination and capillary electrophoresis-based DNA sequencers under the model name CEQ, including the CEQ 8000. The company now produces the GeXP Genetic Analysis System, which uses dye terminator sequencing. This method uses a thermocycler in much the same way as PCR to denature, anneal, and extend DNA fragments, amplifying the sequenced fragments.
=== Pacific Biosciences === Pacific Biosciences produces the PacBio RS and Sequel sequencing systems using a single molecule real time sequencing, or SMRT, method. This system can produce read lengths of multiple thousands of base pairs. Higher raw read errors are corrected using either circular consensus - where the same strand is read over and over again - or using optimized assembly strategies. Scientists have reported 99.9999% accuracy with these strategies. The Sequel system was launched in 2015 with an increased capacity and a lower price.
=== Oxford Nanopore === Oxford Nanopore Technologies' MinION sequencer is based on evolving nanopore sequencing technology to nucleic acid analyses. The device is four inches long and gets power from a USB port. MinION decodes DNA directly as the molecule is drawn at the rate of 450 bases/second through a nanopore suspended in a membrane. Changes in electric current indicate which base is present. Initially, the device was 60 to 85 percent accurate, compared with 99.9 percent in conventional machines. Even inaccurate results may prove useful because it produces long read lengths. In early 2021, researchers from University of British Columbia has used special molecular tags and able to reduce the five-to-15 per cent error rate of the device to less than 0.005 per cent even when sequencing many long stretches of DNA at a time. There are two more product iterations based on MinION; the first one is the GridION which is a slightly larger sequencer that processes up to five MinION flow cells at once. And, the second one is the PromethION which uses as many as 100,000 pores in parallel, more suitable for high volume sequencing.
=== MGI === MGI produces high-throughput sequencers for scientific research and clinical applications such as DNBSEQ-G50, DNBSEQ-G400, and DNBSEQ-T7, under a proprietary DNBSEQ technology. It is based upon DNA nanoball sequencing and combinatorial probe anchor synthesis technologies, in which DNA nanoballs (DNBs) are loaded onto a patterned array chip via the fluidic system, and later a sequencing primer is added to the adaptor region of DNBs for hybridization. DNBSEQ-T7 can generate short reads at a very large scale—up to 60 human genomes per day. DNBSEQ-T7 was used to generate 150 bp paired-end reads, sequencing 30X, to sequence the genome of SARS-CoV-2 or COVID-19 to identify the genetic variants predisposition in severe COVID-19 illness. Using a novel technique the researchers from China National GeneBank sequenced PCR-free libraries on MGI's PCR-free DNBSEQ arrays to obtain for the first time a true PCR-free whole genome sequencing. MGISEQ-2000 was used in single-cell RNA sequencing to study the underlying pathogenesis and recovery in COVID-19 patients, as published in Nature Medicine.
== Comparison == Current offerings in DNA sequencing technology show a dominant player: Illumina (December 2019), followed by PacBio, MGI and Oxford Nanopore.
== References ==