Unconfigured Ad

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • DerIch
    Junior Member
    • Dec 2013
    • 2

    #1

    gsnap: How to output only alignments with minimal number of mismatches?

    Hi there,

    I am aligning paired-end ChIP-Seq data of drosophila transcription factors.

    I would like to have a .sam file with the following alignments reported:
    - A maximum of three mismatches, i.e. three wrong bases (this is the option --max-mismatch=3)
    - But, if there are possible alignments with only one mismatch, and also possible alignments with two mismatches, I want only the alignments with one mismatch reported.

    I thought -M 0 (same as --suboptimal-levels=0) would be my option, but it doesn't work. I think it works on the mapping quality field (i.e. MAPQ).

    The --npaths=1 option doesn't do it for me as well, because it reports only one (the best) alignment, even if there are multiple possible alignments with the minimum number of mismatches.

    I hope I stated my aim clearly. Does anyone know how I could obtain this specific subset of alignments? I fear I might have to resort to Python and code it up by myself, but want to make sure there is no easy solution available first.

Latest Articles

Collapse

  • SEQadmin2
    16S/ITS Profiling vs. Shotgun Metagenomics: What Changes in Your Workflow?
    by SEQadmin2




    NGS has revolutionized clinical microbiology by offering new ways to identify and surveil pathogens without prior knowledge of the target. One popular approach is 16S rRNA and ITS amplicon sequencing, which targets specific microbial markers. But studies are increasingly incorporating shotgun metagenomics, a technique that sequences all DNA from a sample without targeting specific microbial markers. This approach allows more detailed taxonomic classification, detection...
    10-30-2026, 06:46 AM
  • SEQadmin2
    Multiomic Liquid Biopsy: What DNA/RNA Panels Reveal That DNA Alone Can’t
    by SEQadmin2



    Tumors contain complex mixtures of cell populations that evolve in response to treatment and host-specific factors. Tissue biopsies provide only static snapshots of a tumor’s state. But what if we could follow that evolution over time using a minimally invasive technique?

    Liquid biopsies can detect tumor-derived material circulating in the bloodstream, providing a way to study treatment response, detect emerging resistance, and discover new biomarkers. Circulating
    ...
    10-14-2026, 09:55 AM

ad_right_rmr

Collapse

News

Collapse

Topics Statistics Last Post
Started by SEQadmin2, 10-28-2026, 09:57 AM
0 responses
33 views
0 reactions
Last Post SEQadmin2  
Started by SEQadmin2, 10-28-2026, 09:51 AM
0 responses
21 views
0 reactions
Last Post SEQadmin2  
Started by SEQadmin2, 10-22-2026, 11:13 AM
0 responses
72 views
0 reactions
Last Post SEQadmin2  
Started by SEQadmin2, 10-22-2026, 10:48 AM
0 responses
48 views
0 reactions
Last Post SEQadmin2  
Working...