Seqanswers Leaderboard Ad

Collapse

Announcement

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

  • Predicting true SNPs from .vcf file

    The .vcf file contains so many different measurements, and a couple of different quality scores, does anyone have a good empirical idea of which values are the best guidelines to picking out real SNPs from noise and artifacts? I've done about a hundred sanger sequencing reactions on a variety of predicted SNPs at a variety of quality levels, but the picture still isn't very clear.

    For instance these SNPs looked real in the sanger:

    GT:PL:GQ 0/1:20,11,149:13 gcacacacacacacacacacacacacacacacacacacacac gcacacacacacacacacacacacacacacacacacacac 211 DP=95 DP4=17,0,10,2 MQ=48 FQ=214

    GT:PL:GQ 1/1:30,3,0:39 GAA GA 147 DP=10 DP4=0,0,1,6 MQ=48 FQ=-37.3


    These did not confirm with sanger sequencing

    GT:PL:GQ 0/1:24,0,114:27 A C 110 DP=130 DP4=14,35,2,22 MQ=45 FQ=113

    GT:PL:GQ 0/1:40,0,47:42 T G 98.3 DP=71 DP4=17,1,14,0 MQ=44 FQ=101

    Those don't look notably worse than the ones above them, so I'm not sure what I should have looked at to predict that the bottom two were false positives.

    (My a priori assumption was that these variants were all real, because I made a multi-vcf with mpileup with this samples and many sibling animals, and these variants were common to all the animals)

  • #2
    maybe the depth of the bottom two is too high. Have you try the -D options?

    Originally posted by swbarnes2 View Post
    The .vcf file contains so many different measurements, and a couple of different quality scores, does anyone have a good empirical idea of which values are the best guidelines to picking out real SNPs from noise and artifacts? I've done about a hundred sanger sequencing reactions on a variety of predicted SNPs at a variety of quality levels, but the picture still isn't very clear.

    For instance these SNPs looked real in the sanger:

    GT:PL:GQ 0/1:20,11,149:13 gcacacacacacacacacacacacacacacacacacacacac gcacacacacacacacacacacacacacacacacacacac 211 DP=95 DP4=17,0,10,2 MQ=48 FQ=214

    GT:PL:GQ 1/1:30,3,0:39 GAA GA 147 DP=10 DP4=0,0,1,6 MQ=48 FQ=-37.3


    These did not confirm with sanger sequencing

    GT:PL:GQ 0/1:24,0,114:27 A C 110 DP=130 DP4=14,35,2,22 MQ=45 FQ=113

    GT:PL:GQ 0/1:40,0,47:42 T G 98.3 DP=71 DP4=17,1,14,0 MQ=44 FQ=101

    Those don't look notably worse than the ones above them, so I'm not sure what I should have looked at to predict that the bottom two were false positives.

    (My a priori assumption was that these variants were all real, because I made a multi-vcf with mpileup with this samples and many sibling animals, and these variants were common to all the animals)

    Comment

    Latest Articles

    Collapse

    • seqadmin
      Investigating the Gut Microbiome Through Diet and Spatial Biology
      by seqadmin




      The human gut contains trillions of microorganisms that impact digestion, immune functions, and overall health1. Despite major breakthroughs, we’re only beginning to understand the full extent of the microbiome’s influence on health and disease. Advances in next-generation sequencing and spatial biology have opened new windows into this complex environment, yet many questions remain. This article highlights two recent studies exploring how diet influences microbial...
      02-24-2025, 06:31 AM
    • seqadmin
      Quality Control Essentials for Next-Generation Sequencing Workflows
      by seqadmin




      Like all molecular biology applications, next-generation sequencing (NGS) workflows require diligent quality control (QC) measures to ensure accurate and reproducible results. Proper QC begins at nucleic acid extraction and continues all the way through to data analysis. This article outlines the key QC steps in an NGS workflow, along with the commonly used tools and techniques.

      Nucleic Acid Quality Control
      Preparing for NGS starts with isolating the...
      02-10-2025, 01:58 PM

    ad_right_rmr

    Collapse

    News

    Collapse

    Topics Statistics Last Post
    Started by seqadmin, 03-03-2025, 01:15 PM
    0 responses
    28 views
    0 likes
    Last Post seqadmin  
    Started by seqadmin, 02-28-2025, 12:58 PM
    0 responses
    124 views
    0 likes
    Last Post seqadmin  
    Started by seqadmin, 02-24-2025, 02:48 PM
    0 responses
    485 views
    0 likes
    Last Post seqadmin  
    Started by seqadmin, 02-21-2025, 02:46 PM
    0 responses
    241 views
    0 likes
    Last Post seqadmin  
    Working...
    X