Seqanswers Leaderboard Ad

Collapse

Announcement

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

  • TopHat2 error running 'prep_reads'

    Dear community,

    I have a problem with prep_reads running TopHat2, like so many other. I have looked at all previous threads, and that solved my problem only partly.

    I had 12 multiplexed RNA samples that I ran on 6 lanes on an Illumina HiSeq2000. After retrieving the data I made a custom program to demultiplex the samples and combine the data from the 6 lanes. On the resulting fastq files I tried to run TopHat. First I used:

    /tophat/tophat2 -o TophatOutput_sample -p 4 /Bowtie2index/hg19 sample.fq

    That worked for 8 out of 12 samples. After reading a bit on this forum I realized that I had phred quality score 64, so I added --solexa1.3-quals. That solved the issue for another three samples, but still I cannot run TopHat on the last sample. I receive the following error message for that sample:

    [2013-05-28 22:02:25] Beginning TopHat run (v2.0.8b)
    -----------------------------------------------
    [2013-05-28 22:02:25] Checking for Bowtie
    Bowtie version: 2.1.0.0
    [2013-05-28 22:02:25] Checking for Samtools
    Samtools version: 0.1.9.0
    [2013-05-28 22:02:25] Checking for Bowtie index files
    [2013-05-28 22:02:25] Checking for reference FASTA file
    [2013-05-28 22:02:25] Generating SAM header for /data/genomes/hg19/genome/Bowtie2index/hg19
    format: fastq
    quality scale: phred64 (reads generated with GA pipeline version >= 1.3)
    [2013-05-28 22:02:30] Preparing reads
    [FAILED]
    Error running 'prep_reads'
    ---------------------------

    My prep_reads.log is empty.

    I would be very happy if anyone could tell me how to solve the problem!

  • #2
    Problem solved.

    Instead of running TopHat2 I ran Bowtie2 directly on the problematic fq file. Bowtie2 gave a much more concrete error message. It turned out that in the middle of the file I had a huge repeat of /xoo/xoo. I have no idea how it came there, but I reran my previous custom code, and after that it all worked as it should.

    Comment


    • #3
      Originally posted by Kaskar View Post
      Problem solved.

      Instead of running TopHat2 I ran Bowtie2 directly on the problematic fq file. Bowtie2 gave a much more concrete error message. It turned out that in the middle of the file I had a huge repeat of /xoo/xoo. I have no idea how it came there, but I reran my previous custom code, and after that it all worked as it should.
      For future reference, the messages reported to the terminal during a Tophat run are only a minimal summary of the information reported by the underlying programs which Tophat runs. Tophat keeps the much more complete logs of each program in the <output_directory>/logs directory. When your Tophat run failed during Bowtie you could have checked the bowtie log in the logs directory for more detailed information.

      Comment


      • #4
        ok guys please i need some help
        i am very very new to tophat, bowtie samtool colabo.
        i had this error below can some one please explain to me
        thanks

        prep_reads v2.0.0 (3280)
        ---------------------------
        Error: qual length (131) differs from seq length (100) for fastq record HWI-ST365_0157:7:2101:9222:152711#GCGGTC/2!

        gzip: stdout: Broken pipe

        Comment


        • #5
          TopHat2 error running 'prep_reads'

          Have a look at the record for the read mentioned in the error message,
          and see if there is anything obviously wrong with your file.

          Is there some character that your computer system doesn't like
          and is interpreting as a return character, or is it missing a return character
          at the end of one of the lines?

          Comment


          • #6
            ok i have checked the record of the error message, here
            @HWI-ST365_0157:7:2101:9222:152711#GCGGTC/2
            CTGCACCAGCCCGTCGAAGACACATCAGTGACTCCATCATGACTTTTTCTTCATCAATCATTTTGAGAACAGCACCAGCCTTGATCATCGAGTATTCACC
            +HWI-ST365_0157:7:2101:9222:152711#GCGGTC/2
            _bbeeeeeg^ecggfhhiiffhihihihffggiihgfhhbghifiidgefdeghffhhiiiiiiiefegga_cebcbcca^`bcccdccb`a``_bcY_b

            thay are both 100 i do not know why the error.
            i am viturlizing ubuntu on windows 7, could this be an issue?
            kindly assist

            Comment

            Latest Articles

            Collapse

            • seqadmin
              Essential Discoveries and Tools in Epitranscriptomics
              by seqadmin




              The field of epigenetics has traditionally concentrated more on DNA and how changes like methylation and phosphorylation of histones impact gene expression and regulation. However, our increased understanding of RNA modifications and their importance in cellular processes has led to a rise in epitranscriptomics research. “Epitranscriptomics brings together the concepts of epigenetics and gene expression,” explained Adrien Leger, PhD, Principal Research Scientist...
              04-22-2024, 07:01 AM
            • 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

            ad_right_rmr

            Collapse

            News

            Collapse

            Topics Statistics Last Post
            Started by seqadmin, Today, 08:47 AM
            0 responses
            12 views
            0 likes
            Last Post seqadmin  
            Started by seqadmin, 04-11-2024, 12:08 PM
            0 responses
            60 views
            0 likes
            Last Post seqadmin  
            Started by seqadmin, 04-10-2024, 10:19 PM
            0 responses
            59 views
            0 likes
            Last Post seqadmin  
            Started by seqadmin, 04-10-2024, 09:21 AM
            0 responses
            54 views
            0 likes
            Last Post seqadmin  
            Working...
            X