Tag Archives: next generation sequencing

The 454 DNA sequencing?

454 sequencing was first propelled by Life Science in 2005 with the beginning of first next-generation DNA sequencing which had made a great innovation in the field of DNA sequencing.


454 strategy is the method to arrange DNA proportionate up to 1 billion bases in a solitary day.

454 DNA sequencing

Compared to the other methods, 454 is less expensive and speedier used to the arrangement.

In any cases, without its shortcomings, the stage is nothing. To recognize the quantity of the bases in indistinguishable bases, it experiences issues, like AAAA.

The work flow of 454 sequencing

To start the procedure, a specimen of double-stranded DNA is needed.

The DNA separates into 400-600 base pieces through cutting the DNA at a particular focuses by utilizing the confinement compounds.

Short groupings of DNA are joined to the DNA parts, which is called connectors.

In the blend, minor resin dots are added.

On the heads, the DNA groupings are corresponding to arrangements on the connectors, which permit the DNA part can tie to the dots straightforwardly in a perfect section.

At the point, the DNA pieces append to the DNA on the dots to join the the double-strand together, getting the single-stranded DNA.

After that, on each dot, the DNA parts are replicated various times with polymerase chain response. This step can makes huge number of indistinguishable duplicates of the DNA sequencing.

To evacuate any one that has either neglected or connected any DNA which contains more than kind of DNA section, the globules are sifted.

At that point, all the remaining globules are placed into the wells. And the enzyme dots contain the DNA polymerase for the purpose of the sequencing response.

On the globules, the polymerase catalyst and groundwork also join to the DNA section.

Nucleotide bases are added to the wells at once.

At the point when every base is consolidated into the DNA. Camera will record it that the light is given out.

By plotting this example of light power on a diagram, the succession of the first bit of DNA can be decoded.

Genomic sequencing–Next Generation Sequencing

The finish of Human Genome Project is a milestone for genome research. With ten-year development, the technology of genomic sequencing has changed a lot, which greatly improved the efficiency of sequencing. Last week researchers announced their result of UK10K project. Since it was proposed by David Cameron in 2014, this big project has analyzed the whole genome of nearly ten thousand people for only one year. Next generation sequencing plays an important role here.

Next generation sequencing, also called deep sequencing or high throughput sequencing, is a sequencing technology to meet the need of all kinds of research. The main characteristic of next generation sequencing is sequencing by synthesis. It has a higher throughput, and is more rapid but cost less than Sanger sequencing.
Roche 454
The coming of Genome Sequencer 20 System opened the gate of next generation sequencing. This is a high throughput genome sequencing system based on pyrosequencing technology which was introduced by 454 company. Through the purchase, Roche owned this technology and upgraded it. This is the 454 GS FLX sequencer.

Roche 454

(Roche 454 GS FLX sequencer)

The biggest advantage of Roche 454 is its reads. It can remain a high accuracy over 400bp reads. That’s the reason that it can be widely used in de novo sequencing, genome analysis and transcriptome analysis.
In 2006, Solexa company also launched its own NGS system, Genome Analyzer. For its advantage of cost, compatibility and operability, Solexa has become the most widely used technology in sequencing. From GA to Illumina Hiseq 2000/2500, the Solexa technology also changed a lot. Now it only takes ten days for the completion of three human whole genome sequences. The application of Solexa contains de novo sequencing, re-sequencing, small RNA sequencing, lncRNA sequencing, transcriptomics sequencing and etc.



(Illumina Hiseq 2000)


As one of the magnates in sequencing industry, ABI is the monopolistic company in Sanger sequencing. However, ABI did not grab the chance of NGS. Until 2007, ABI purchased a research company, Agencourt, and launched its SOLID sequencing platform. The whole name is Sequencing by Oligo Ligation Detection. Compared to Roche 454 and Solexa, SOLID has the highest accuracy and flexibility. It can be used to the whole genome mapping analysis, and more RNA research.