The Roche/454 Life Sciences GS FLX and GS Junior: an obituary

You were a pioneer, the first successful ‘next generation’ (if you’ll pardon the term) commercially available sequencing platform in 2005. You just beat Solexa, but it was a fairly close call.

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The author (left) with colleagues showing off their 454 GS FLX

Your greatest accomplishment was to show that pyrosequencing, which was around for a while already, could be scaled up, both in terms of read length and parallelisation. You started the revolution in DNA sequencing, suddenly making large scale genomic projects available to labs that traditionally only could dream of been doing such projects at this scale.

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Developments in high throughput sequencing – July 2016 edition

This is the fifth edition of this visualisation, previous editions were in June 2015, June 2014, October2013 and December 2012.

As before, full run throughput in gigabases (billion bases) is plotted against single-end read length for the different sequencing platforms, both on a log scale. Yes, I know a certain new instrument (different from last time) seems to be missing, hang on, I’m coming back to that…

developments_in_high_throughput_sequencing

Notable changes from the June 2015 edition

  • I added the Illumina MiniSeq
  • I added the Oxford Nanopore MinION. The read length for this instrument was based on the specifications for maximal output and number of reads from the company’s website. The two data points represent ‘regular’ and ‘fast’ modes.
  • I added the IonTorrent S5 and S5XL. You may notice that the line for this instrument has a downward slope, this is due to the fact that the 400 bp reads are only available on the 520 and 530 chip, but not the higher throughput 540 chip, making the maximum throughput for this read length lower than for the 200 bp reads.

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Developments in high throughput sequencing – June 2015 edition

This is the fourth edition of this visualisation, previous editions were in June 2014, October 2013 and December 2012.

As before, full run throughput in gigabases (billion bases) is plotted against single-end read length for the different sequencing platforms, both on a log scale. Yes, I know a certain new instrument seems to be missing, hang on, I’m coming back to that…

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A hybrid model for a High-Performance Computing infrastructure for bioinformatics

I work for the Norwegian High-Throughput Sequencing Centre (NSC), but at the Centre for Ecological and Evolutionary Synthesis (CEES). At CEES, numerous researchers run bioinformatic analyses, or other computation-heavy analyses, for their projects. With this post, I want to describe the infrastructure we use for calculations and storage, and the reason why we chose to set these up the way we did.

In general, when one needs high-performance compute (HPC) infrastructure, a (group of) researcher(s) can purchase these and locate them in or around the office, or use a cloud solution. Many, if not most, universities offer a computer cluster for their researchers’ analysis needs. We chose a hybrid model between the universitys HPC infrastructure and setting up one ourselves. In other words, our infrastructure is a mix of self-owned, and shared resources that we either apply for, or rent.

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On graph-based representations of a (set of) genomes

In 1986, in a letter to the journal Nature, James Bruce Walsh and Jon Marks lamented that the upcoming human genome sequencing project “violates one of the most fundamental principles of modern biology: that species consist of variable populations of organisms”. They further wrote: “As molecular biologists generally ignore any variability within a population, the individual whose haploid [sic] genome will be chosen will provide the genetic benchmark against which deviants are determined”. They conclude that ” ‘the’ genome of ‘the’ human will be sequenced gel by acrylamide gel”.

We have come a long way when it comes to taking population variation into account in molecular/genetic/genomic studies. But these sentiments, expressed already in 1986, echo some of the trends in the human genetics field: the move away from a single, linear representation of ‘the’ human genome. In this post I will provide some background, explain the reasons for moving towards graph-based representations, and indicate some challenges associated with this development.

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Thoughts on a possible Assemblathon3

The Genome10K meeting is ongoing (I am not attending but following through twitter). Today, there will be a talk by Ian Korf about the feasibility of an Assemblathon 3 contest (see this tweet and the schedule). Earlier the @Assemblathon twitter account asked for a wishlist for an Assemblathon 3 through the hashtag #A3wishlist. With this post I want to share my opinion on what a possible Assemblathon 3 could and/or should be about.

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My review of “MinION nanopore sequencing identifies the position and structure of a bacterial antibiotic resistance island”

Earlier this week, the first paper was published describing the use of Oxford Nanopore MinION data to solve a biological question. The paper, entitled “MinION nanopore sequencing identifies the position and structure of a bacterial antibiotic resistance island” came out in Nature Biotechnology (ReadCube link).

I was a reviewer for this manuscript. I have posted my two (signed) review reports on publons. As data and code were made available by the authors (as it should be), I made a (mostly successful) effort to reproduce the computational part of the paper. After I was done with the review report of the second version I could not help myself to have a further look at some of the results. This led to me sending some plots to the authors, and one of these plots ended up becoming figure 1. This was a lot of fun to see in the final version.

Below are some excerpts of the review reports.
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