Seqanswers Leaderboard Ad

Collapse

Announcement

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

  • Low mapping rate for RNAseq 2x150 trimmed data

    I just got a data set from my collaborator. 2 X 150 bps, Illumina RNAseq data for human samples. We did QC on the data and trimmed it to remove adaptors and low quality bases. Then I use tophat2 to map them to hg19 in three ways:

    1. paired end mapping with default parameters;
    2. single end mapping for each end separately;
    3. paired end mapping with inner distance between the two ends to have a mean of 0 and sd=50;

    Mapping rate for 1 and 3 are both around 45%. But mapping rate for 2 is around 75%. So most of the reads are mappable but cannot be paired even when the inner distance between the two ends can be 0 or negative (if the distance can go negative). I took a look at the BAM files for the accepted hits. It looks like read pairs with alignment

    ------------>>>----------------
    ------------<<<<----------------

    can be paired. But read pairs with alignment

    -------------->>>>--------------
    -----------<<<<---------------

    can not be paired. Does any one know why and how I can gain those unpaired alignment back? Thanks in advance!

Latest Articles

Collapse

  • seqadmin
    Recent Advances in Sequencing Analysis Tools
    by seqadmin


    The sequencing world is rapidly changing due to declining costs, enhanced accuracies, and the advent of newer, cutting-edge instruments. Equally important to these developments are improvements in sequencing analysis, a process that converts vast amounts of raw data into a comprehensible and meaningful form. This complex task requires expertise and the right analysis tools. In this article, we highlight the progress and innovation in sequencing analysis by reviewing several of the...
    05-06-2024, 07:48 AM
  • 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

ad_right_rmr

Collapse

News

Collapse

Topics Statistics Last Post
Started by seqadmin, 05-14-2024, 07:03 AM
0 responses
19 views
0 likes
Last Post seqadmin  
Started by seqadmin, 05-10-2024, 06:35 AM
0 responses
44 views
0 likes
Last Post seqadmin  
Started by seqadmin, 05-09-2024, 02:46 PM
0 responses
54 views
0 likes
Last Post seqadmin  
Started by seqadmin, 05-07-2024, 06:57 AM
0 responses
42 views
0 likes
Last Post seqadmin  
Working...
X