General musings from the MacVector team about sequence analysis, molecular biology, the Mac in general and of course your favorite sequence analysis app for the Mac!

Tag Archives: velvet

How to split large fastq files for more manageable assemblies

We’ve previously discussed how important it can be to make sure you are using the appropriate number of fastq reads from an NGS experiment to ensure you obtain the results you are looking for. Using too many reads can confuse algorithms with the massive coverage increasing mis-assemblies due to background errors in the reads. In […]

Posted in Techniques, Tips | Also tagged , , | Comments closed

Balancing Velvet KMER and coverage

The Velvet assembly algorithm in MacVector is blazingly fast and generates excellent assemblies. However, you do have to be careful when assembling NGS data to be sure that the parameters you submit are appropriate for the data you are assembling in order to get optimal results. By far the most important parameter is the KMER […]

Posted in Tips | Also tagged , , | Comments closed

Assemble bacterial genomes in minutes on your Mac laptop

MacVector with Assembler contains some remarkably powerful algorithms for assembling Next Generation Sequencing (NGS) data. Not so long ago, you needed a powerful Linux server with lots of memory for de novo assembly of whole genomes. But with advances in the efficiency of algorithms and improvements in hardware, it is now possible to assemble quite […]

Posted in Tips | Also tagged , , , | Comments closed

An overview of assembling sequencing data with MacVector’s Assembler plugin

To assemble various types of sequencing reads, follow these steps. Choose File | New | Assembly Project to create a new empty project file. Then follow one of the following: To create a de novo assembly from Sanger reads Click on the Add Reads tool bar button, then select the sequence files you wish to […]

Posted in Techniques, Tips | Also tagged , , , , | Comments closed

101 things you (maybe) didn’t know about MacVector: #51 – Rapid assembly of genomes with Velvet and SPAdes

Not so long ago, to assemble even a small genome with Next Generation Sequencing data required an array of clustered computers and a lot of patience. But improvements in algorithms and hardware mean that it is now realistic to assemble bacterial genomes, or even smaller eukaryotic genomes using MacVector on a modest laptop machine. MacVector […]

Posted in 101 Tips | Also tagged , | Comments closed

MacVector Talk: July 2014: Sequence assembly on the desktop with MacVector and Assembler.

Generating sequencing data is cheaper than it has ever been. However, with this increase in data has come a problem with easy analysis. Assembling 20 reads for your site directed mutagenesis project is easy. Why should dealing with 20 million reads of your bacterial genome be any harder? In our Summer newsletter we talk about […]

Posted in newsletter | Also tagged , , , | Comments closed

Accessing BAM files from an Assembly Project file

All assemblies are stored using the BAM file format. This is a binary file that stores each read and where and which consensus/contig/reference it is mapped against. It is a compressed version of the pure text SAM format. For some post assembly tasks it is necessary to do further processing on the BAM file. To […]

Posted in Tips | Also tagged , , | Comments closed

de novo assembly with Velvet

Velvet is a short read aligner that works very well on a wide variety of reads. Velvet excels at de novo assembly of sequencing reads from second and newer generation sequencers. In our latest release, MacVector 13, we’ve added Velvet to Assembler. This joins the existing tools, Phrap for Sanger sequencing reads and Bowtie for […]

Posted in Releases, Tips | Also tagged , , | Comments closed