Unconfigured Ad

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • caputcastellae
    Junior Member
    • Apr 2010
    • 1

    #1

    Extract sequences from a FASTQ file based on another file

    I have two files:

    file 1: fastaq XXGB file
    file 2: list of a few FASTQ ID headers formatted as follows:

    @M01032:192:000000000-AAEFT:1:1101:10100:1004 2:N:0:1
    @M01032:192:000000000-AAEFT:1:1101:10100:1004 1:N:0:1

    Is there an easy way (perl?) to generate a third file with the info (including the ID headers of the targeted sequences (file 2)?

    Thanks!
  • GenoMax
    Senior Member
    • Feb 2008
    • 7142

    #2
    There are probably more elegant ways of doing this but you can try this now. With that said (in tcshell and assuming that your sequences do not wrap around)

    Code:
    $ foreach i (`cat ./file_of_ID_you_need`)
    foreach? grep ^$i -A 3 your_sequence_file >> new_sequence_file
    foreach? end

    Comment

    • gandalf886
      Member
      • Feb 2013
      • 11

      #3
      perhaps this?
      Code:
      grep --no-group-separator -A 3 -Fxf file_2 file_1 > output
      Originally posted by GenoMax View Post
      There are probably more elegant ways of doing this but you can try this now. With that said (in tcshell and assuming that your sequences do not wrap around)

      Code:
      $ foreach i (`cat ./file_of_ID_you_need`)
      foreach? grep ^$i -A 3 your_sequence_file >> new_sequence_file
      foreach? end

      Comment

      • GenoMax
        Senior Member
        • Feb 2008
        • 7142

        #4
        If sequence file is compressed then extending gandalf886's suggestion
        Code:
        $ zmore sample.fastq.gz | grep -A 3 -Fxf  file_of_IDs > new_sequence_file
        or

        Code:
        $ zcat sample.fastq.gz | grep -A 3 -Fxf  file_of_IDs > new_sequence_file

        Comment

        Latest Articles

        Collapse

        • 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
        • SEQadmin2
          New Genomics Technologies Take Aim at Long-Standing Limits
          by SEQadmin2


          Researchers using sequencing and genomics tools often have to make trade-offs. They can choose between speed or scale, short reads or long-range information, or targeted panels or a view of the whole transcriptome. New technologies that have been released this year are built to address those tough choices.

          We asked six companies the same four questions to learn about their latest products. The new technologies bring a lot to the table, including rethinking sequencing
          ...
          09-28-2026, 10:25 AM

        ad_right_rmr

        Collapse

        News

        Collapse

        Topics Statistics Last Post
        Started by SEQadmin2, Yesterday, 11:13 AM
        0 responses
        16 views
        0 reactions
        Last Post SEQadmin2  
        Started by SEQadmin2, Yesterday, 10:48 AM
        0 responses
        17 views
        0 reactions
        Last Post SEQadmin2  
        Started by SEQadmin2, 10-15-2026, 10:52 AM
        0 responses
        35 views
        0 reactions
        Last Post SEQadmin2  
        Started by SEQadmin2, 10-14-2026, 05:39 AM
        0 responses
        42 views
        0 reactions
        Last Post SEQadmin2  
        Working...