One of my favorite in-class exercises is The Assembly Exercise, in which I provided "shotgun sequence" from some English text and ask the students to assemble it. Normally I provide a printout of about 10-20 pages of reads with range of read lengths, error rates, and single/paired end sequences …
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These talk notes are for my talk at the 2012 Argonne Soil Metagenomics Workshop.
The slides are available for viewing and download here, on Slideshare.
I'm going to be talking about our assembly pipeline for soil metagenomes.
Much of this work was done by …
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One of the biggest problems with basic sequence analysis -- some would say the biggest problem -- is the error rate. If our sequencing reads were error-free, both assembly and mapping would be much, much easier. Alas, Illumina reads have a 0.1-1% error rate per base, and PacBio has an error …
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I'm at the MBL STAMPS course, "Strategies and Techniques for Analyzing Microbial Population Structure," and one of the things I needed to address in my morning talk was the role that the k parameter plays in de Bruijn graph assemblers.
In most de Bruijn assemblers that I have used -- Velvet …
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Suppose you have a community that has two organisms in it, at widely varying abundances. What can you do?
Partitioning takes this mixed distribution and, based on graph connectivity, splits the reads into two bins. Thus, you go from this:
to this:
where the reads are …
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This is the story behind our PNAS paper, "Scaling Metagenome Assembly with Probabilistic de Bruijn Graphs" (released from embargo this past Monday).
Why did we write it? How did it get started? Well, rewind the tape 2 years and more...
There we were in May 2010, sitting on 500 million …
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