Unconfigured Ad

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • mudshark
    Senior Member
    • Jan 2009
    • 138

    #31
    Originally posted by captainentropy View Post
    @mudshark. You've tried quite a few programs. More than I have. Since I use QuEST the most could you tell me why you think it doesn't perform well? Did you use default or advanced parameter settings? This paper found most peak-calling programs to have high agreement between high-value peaks and qPCR verification data http://www.plosone.org/article/info:...l.pone.0011471
    based on my prior-knowledge system i can do a very good performance estimation of the tools. basically i know all the binding sites genome-wide without having to do ChIP mappings.

    of course, I am working in Drosophila and QuEST e.g. has been 'optimized' for mouse/human whatever that means. but in essence, QuEST has a very low sensitivity and given the low sensitivity a rather bad specificity COMPARED to other tools such as SICER, spp, and MACS.

    my experience.. other people might have a different one.

    (and of course i find QuEST very poorly documented - what are the advanced parameters?)

    Comment

    • captainentropy
      Member
      • Mar 2009
      • 89

      #32
      mudshark, if you include the "-advanced" option in the QuEST command you will have the option to configure all of the parameters such as bandwidth, region size, mappable genome fraction, ChIP enrichment, peak shift, etc. You can also control the peak collapsing parameters too.

      I recommend using the advanced option and at a minimum change the mappable genome fraction to something more accurate. The fraction is a function of the read length and percentage of mappable sequence (i.e. the non-repetitive sequences) for your genome. The longer the read length the larger the mappable fraction. The default in QuEST is 0.75 which (for hg18) corresponds to a readlength of 26nt. We are getting read lengths of 38nt and longer which increases the fraction to 0.82 and up. Using this number has resulted in a noticeable increase in number of peaks called.

      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, 10-22-2026, 11:13 AM
      0 responses
      27 views
      0 reactions
      Last Post SEQadmin2  
      Started by SEQadmin2, 10-22-2026, 10:48 AM
      0 responses
      20 views
      0 reactions
      Last Post SEQadmin2  
      Started by SEQadmin2, 10-15-2026, 10:52 AM
      0 responses
      36 views
      0 reactions
      Last Post SEQadmin2  
      Started by SEQadmin2, 10-14-2026, 05:39 AM
      0 responses
      43 views
      0 reactions
      Last Post SEQadmin2  
      Working...