Seqanswers Leaderboard Ad

Collapse

Announcement

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

  • BWA errors after quality trimming

    After I use the "-q 20" option in bwa aln I start getting errors down the road eg when i run ValidateSamFile in picard I get lots of "Mate negative strand flag does not match read negative strand flag of mate" and then "Sequence and quality are inconsistent" errors as well. I have run all the same commands without the -q option without these problems. I am very new to all this and not sure where I'm going wrong!

  • #2
    A little late, but I am also running -q option and curious if you identified the problem.

    Comment


    • #3
      No I ended up just running it without trimming as I decided it wasn't really necessary

      Comment


      • #4
        This is a bug in BWA. If you use -q it puts the trimmed nucleotide read in the output SAM file but the quality sequence is not trimmed at all and thus there is a difference in the length of the read and the length of the quality string. Either use some third party tool like trimgalore to trim your fastq reads before aligning and don't use BWA -q option at all OR use some script that takes SAM file and trims off the base quality string accordingly.

        PS:This post may help- http://www.biostars.org/post/show/13...or-space-data/

        Comment

        Latest Articles

        Collapse

        • seqadmin
          Advancing Precision Medicine for Rare Diseases in Children
          by seqadmin




          Many organizations study rare diseases, but few have a mission as impactful as Rady Children’s Institute for Genomic Medicine (RCIGM). “We are all about changing outcomes for children,” explained Dr. Stephen Kingsmore, President and CEO of the group. The institute’s initial goal was to provide rapid diagnoses for critically ill children and shorten their diagnostic odyssey, a term used to describe the long and arduous process it takes patients to obtain an accurate...
          12-16-2024, 07:57 AM
        • seqadmin
          Recent Advances in Sequencing Technologies
          by seqadmin



          Innovations in next-generation sequencing technologies and techniques are driving more precise and comprehensive exploration of complex biological systems. Current advancements include improved accessibility for long-read sequencing and significant progress in single-cell and 3D genomics. This article explores some of the most impactful developments in the field over the past year.

          Long-Read Sequencing
          Long-read sequencing has seen remarkable advancements,...
          12-02-2024, 01:49 PM

        ad_right_rmr

        Collapse

        News

        Collapse

        Topics Statistics Last Post
        Started by seqadmin, 12-17-2024, 10:28 AM
        0 responses
        23 views
        0 likes
        Last Post seqadmin  
        Started by seqadmin, 12-13-2024, 08:24 AM
        0 responses
        42 views
        0 likes
        Last Post seqadmin  
        Started by seqadmin, 12-12-2024, 07:41 AM
        0 responses
        28 views
        0 likes
        Last Post seqadmin  
        Started by seqadmin, 12-11-2024, 07:45 AM
        0 responses
        42 views
        0 likes
        Last Post seqadmin  
        Working...
        X