Seqanswers Leaderboard Ad

Collapse

Announcement

Collapse
No announcement yet.
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Weird quality issue

    Dear all,
    I just started working on an Ion Proton de novo genome sequencing project. Our service provider sent us the .fastq file, and, as I try to load it either onto Newbler or CLC Workbench (as somebody suggested me), both programs end up warning me about problems with the file.
    CLC Genomics Workbench fails to import the file, warning me about an "unexpected end of file."
    Newbler loads it, but, as I start assembling, it warns me about the presence of lots of sequences with long names, which renders them useless.
    Only MIRA seems not to care about anything, and starts assembling.
    I think the issue might be related to the quality data, since converting it to a simple .fasta file makes everything work very fine. Am I right? Have you already experienced such a problem?

    -MikeT

  • #2
    Is there any sort of cross platform (PC/Mac/Linux) transfer of files involved? Did you get the files on a disk or were they download from the provider (via a web link/ftp)?

    Comment


    • #3
      Originally posted by GenoMax View Post
      Is there any sort of cross platform (PC/Mac/Linux) transfer of files involved? Did you get the files on a disk or were they download from the provider (via a web link/ftp)?
      We had to transfer the files via FTP.

      -MikeT

      Comment


      • #4
        I wonder if they were somehow corrupted during transfer (may want to try a binary format transfer as an alternate).

        Can you try to open the files in FastQC (http://www.bioinformatics.babraham.a...ojects/fastqc/) to get a general idea about quality of data contained within these files (and to see if FastQC complains about the file format)?

        Comment


        • #5
          Yes, I managed to open it up with PRINSEQ, and it didn't complain about the format; also, quality scores ranged up to about 25, which shouldn't be that bad for Ion Torrent. However, FastQ Groomer on Galaxy couldn't handle the file and ended with an error. If you wish, I can try to post the first sequences and related quality scores tomorrow.

          -MikeT

          Comment

          Latest Articles

          Collapse

          • seqadmin
            Current Approaches to Protein Sequencing
            by seqadmin


            Proteins are often described as the workhorses of the cell, and identifying their sequences is key to understanding their role in biological processes and disease. Currently, the most common technique used to determine protein sequences is mass spectrometry. While still a valuable tool, mass spectrometry faces several limitations and requires a highly experienced scientist familiar with the equipment to operate it. Additionally, other proteomic methods, like affinity assays, are constrained...
            04-04-2024, 04:25 PM
          • seqadmin
            Strategies for Sequencing Challenging Samples
            by seqadmin


            Despite advancements in sequencing platforms and related sample preparation technologies, certain sample types continue to present significant challenges that can compromise sequencing results. Pedro Echave, Senior Manager of the Global Business Segment at Revvity, explained that the success of a sequencing experiment ultimately depends on the amount and integrity of the nucleic acid template (RNA or DNA) obtained from a sample. “The better the quality of the nucleic acid isolated...
            03-22-2024, 06:39 AM

          ad_right_rmr

          Collapse

          News

          Collapse

          Topics Statistics Last Post
          Started by seqadmin, 04-11-2024, 12:08 PM
          0 responses
          18 views
          0 likes
          Last Post seqadmin  
          Started by seqadmin, 04-10-2024, 10:19 PM
          0 responses
          22 views
          0 likes
          Last Post seqadmin  
          Started by seqadmin, 04-10-2024, 09:21 AM
          0 responses
          16 views
          0 likes
          Last Post seqadmin  
          Started by seqadmin, 04-04-2024, 09:00 AM
          0 responses
          47 views
          0 likes
          Last Post seqadmin  
          Working...
          X