Unconfigured Ad

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts
  • Arthis
    Junior Member
    • Mar 2013
    • 6

    gsAssembler:

    Hi guys,

    I have been provided with two 454 sequencing de novo assemblies, which were created with Newbler 2.3. We do plan to reassemble the reads on our own as soon as we get access to a PC powerful enough, but in the mean time I was hoping to have a look at the flowgrams for our reads.

    It is my understanding that I'll be able to see the flowgrams for each read if I open up the assembly project in gsAssembler. I don't know of any other way to view the flowgrams (although I have extracted the .flow file with sffinfo, I just don't know of any programs that will show it me in graph form). If there are other programs out there that can show me that data, please let me know.

    However, I have installed the Roche 2.8 data analysis programs on my laptop (Ubuntu 12.10) and receive the following error when I open the projects:

    Unable to launch back-end programs to read alignment results.
    This usually occurs if the project is in use by another instance of the program, if a computation of the project is being run from the command line, or if one or more of the project's read files have been moved from their original locations.
    If that is not the case, then some data indices may be in an inconsistent state.
    Performing a full (non-incremental) analysis may remedy the situation.
    If not, please report this error to your customer support representative.
    At this point, the alignment files and flowgram tabs are greyed out, although the other tabs display as expected.

    The read files have been moved in the sense that the entire working directory assembly has been moved to this computer, although as far as I'm aware the structure within that directory is the same. (I have no way of knowing, however).

    I did search google already, and it was suggested that not having read/write permissions for the assembly directory might be the problem. However, I ensured that I did have that permission for the assembly directory and it did not solve the problem.

    So, is there any way for me to fix this problem without reassembling the data? I'm doing this on my own personal laptop, so reassembling is out of the question.
    Last edited by Arthis; 03-08-2013, 06:48 AM.
  • Arthis
    Junior Member
    • Mar 2013
    • 6

    #2
    Okay, it looks like all you need to do is edit 454AssemblyProject.xml and alter the two <path> fields to point to the new location of the assembly directory and the new location of the .sff file.

    Comment

    • Arthis
      Junior Member
      • Mar 2013
      • 6

      #3
      Does anyone know if it is possible to view the flowgram for the entire read, rather than just the trimmed read?

      I know that, inside the .sff file, each read begins and ends with lowercase letters that fall below a specific quality threshold. I was hoping to look at the flowgram of the uppercase and lowercase regions to see how they compare. When I checked out the flowgram in for a read in my assembly, it only shows the trimmed read with the uppercase letters.

      Comment

      • Arthis
        Junior Member
        • Mar 2013
        • 6

        #4
        Also, does anyone know exactly how the low quality ends are determined by the 454 machine?

        Comment

        Latest Articles

        Collapse

        • SEQadmin2
          Nine Things a Sample Prep Scientist Thinks About Before Sequencing
          by SEQadmin2


          I’m not a sequencing expert. I’m a purification scientist who uses NGS to evaluate workflows my group develops. With this perspective, we think about the sample first and the NGS workflow second. The sequencer is an exceptionally honest reporter, but it can only report on what you give it, so whether you get clean, interpretable data from an NGS workflow is largely determined before you begin.

          Here are nine questions we think about, in roughly the order they matter, before...
          06-18-2026, 07:11 AM
        • SEQadmin2
          From Collection to Sequencing: Why Sample Preparation and Preservation Define Sequencing Data
          by SEQadmin2


          Data variability is still an issue in sequencing technologies despite the advances in reproducibility and accuracy of these platforms. But the problem does not originate in the sequencing itself, but in the previous steps, before the sample reaches the sequencer.


          The first step is collection, followed by preservation and sample preparation for analysis. Most scientists overlook those steps, but not being careful might just be skewing the experiment’s results.
          ...
          06-02-2026, 10:05 AM

        ad_right_rmr

        Collapse

        News

        Collapse

        Topics Statistics Last Post
        Started by SEQadmin2, Today, 11:10 AM
        0 responses
        6 views
        0 reactions
        Last Post SEQadmin2  
        Started by SEQadmin2, 06-17-2026, 06:09 AM
        0 responses
        41 views
        0 reactions
        Last Post SEQadmin2  
        Started by SEQadmin2, 06-09-2026, 11:58 AM
        0 responses
        102 views
        0 reactions
        Last Post SEQadmin2  
        Started by SEQadmin2, 06-05-2026, 10:09 AM
        0 responses
        123 views
        0 reactions
        Last Post SEQadmin2  
        Working...