Unconfigured Ad

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts
  • bob-loblaw
    Member
    • Jun 2012
    • 59

    Does RNA-Seq sequence randomly?

    i.e. if I were to select the first 1000 reads in a fastq file of RNA-Seq data, could they be considered 1000 random reads?
  • westerman
    Rick Westerman
    • Jun 2008
    • 1104

    #2
    Depends on which sequencing technology you are using and where your file came from. In general ... if the reads are directly off of a sequencer then the reads will be random in terms of the molecules sequences but will be ordered in terms of where on the plate/slide/etc. the sequencing occurred. Thus if there are problems with the sequencer (bubbles, poor optics, etc.) you can see non-random effects.

    Comment

    • maubp
      Peter (Biopython etc)
      • Jul 2009
      • 1544

      #3
      So no, the first (and last reads) in the file will usually be from the edge of the plate/slide/tile and therefore be worse quality than average.

      Comment

      • bob-loblaw
        Member
        • Jun 2012
        • 59

        #4
        Originally posted by westerman View Post
        Depends on which sequencing technology you are using and where your file came from. In general ... if the reads are directly off of a sequencer then the reads will be random in terms of the molecules sequences but will be ordered in terms of where on the plate/slide/etc. the sequencing occurred. Thus if there are problems with the sequencer (bubbles, poor optics, etc.) you can see non-random effects.
        Okay thanks, it was an illumina hi-seq machine

        Comment

        Latest Articles

        Collapse

        • SEQadmin2
          Advanced Sequencing Platforms Tackle Neuroscience’s Toughest Genomics Problems
          by SEQadmin2



          Genomics studies in neuroscience face a special challenge due to the brain’s complexity and scarcity of samples. Mapping changes in cell type and state using conventional next-generation sequencing methods remains challenging. Advances in technologies like single-cell sequencing, spatial transcriptomics, and long-read sequencing have opened the door to deeper studies of the brain and diseases like Alzheimer’s, amyotrophic lateral sclerosis (ALS), and schizophrenia.
          ...
          07-09-2026, 11:10 AM
        • SEQadmin2
          Cancer Drug Resistance: The Lingering Barrier to Rising Survival
          by SEQadmin2



          Cancer survival rates have significantly increased in the last few decades in the United States, reaching a combined 70% 5-year survival rate by 2021. Behind this number, there are years of research to find new therapies, drug targets, and early detection methods. But there is one core challenge that keeps slowing down these advances, and it’s about drug resistance.

          There is no single reason why many patients don’t respond to treatment as expected. Cancer is...
          07-08-2026, 05:17 AM
        • GATTACAT
          Reply to Nine Things a Sample Prep Scientist Thinks About Before Sequencing
          by GATTACAT
          Love this - good data definitely starts from good input, and poor input can only give relatively poor data. I particularly like the mention of Nanodrop/absorbance based methods for quantification. It's such a toss up if you'll get an accurate reading or what amounts to a randomly generated number, and a lot of library/sequencing related issues can be traced back to poor quant.
          07-01-2026, 11:43 AM

        ad_right_rmr

        Collapse

        News

        Collapse

        Topics Statistics Last Post
        Started by SEQadmin2, 07-13-2026, 10:26 AM
        0 responses
        28 views
        0 reactions
        Last Post SEQadmin2  
        Started by SEQadmin2, 07-09-2026, 10:04 AM
        0 responses
        37 views
        0 reactions
        Last Post SEQadmin2  
        Started by SEQadmin2, 07-08-2026, 10:08 AM
        0 responses
        25 views
        0 reactions
        Last Post SEQadmin2  
        Started by SEQadmin2, 07-07-2026, 11:05 AM
        0 responses
        35 views
        0 reactions
        Last Post SEQadmin2  
        Working...