This is a test version of Biostars. For the public version, visit https://www.biostars.org.
Unable to view BAM files in IGV

I am trying to open a BAM file (data from human tumor) in IGV to look for mutations in a specific region. However I am not able to view anything on the alignment track.

I am fairly new to IGV and am not sure what I am doing wrong

I installed IGV recently (Java included for MacOS). The .bam and .bam.bai files are in the same folder I am trying to load the file from.

I did not change anything in the preferences when I initially tried loading the file and still saw nothing in the alignment track after zooming all the way in !

enter image description here

macos igv

are you just sure there is any read overlapping the interval ?

what is the output of:

samtools view your.bam "chr7:30387445-30387516"

It would be great if you told us what you did beforehand. Did you sorted and indexed your bam file?

Hi. Yes the bam file is already sorted and indexed. I replied to my post earlier saying that the problem is solved now (After closing and opening IGV several times and zooming in and out, the reads are finally showing).

I guess the older replies to this post disappeared after the image which was a separate comment was moved by another user to my original post

I've moved things around and the answer should be visible now. Sorry for the confusion!

1 answer

I realized I focused on the wrong region in the screenshot when you asked what the output is for the particular region in the image. I went back to IGV to focus on the correct region (which I had already done like 80 times before), and lo and behold, I can suddenly see reads and everything else in the alignment track! Thank you

You also appear to be using hg19 genome. If that is not the correct genome build then you could be looking at a wrong region. Be sure to choose the correct genome build in drop-down menu.

Log in to answer this question.