QC prior to bacterial genome assembly
0
1
Entering edit mode
4.5 years ago
Pegasus ▴ 120

Hi all,

I am analyzing raw data of Illumina reads for bacterial (Wole Genome Sequencing) using tools on the galaxy website. I used trimmomatic, and trim-Galore to remove adapters and low-quality readers.

Fastqc analysis of trimmed reads gave me this report!

Summary

Basic statistics

Per base sequence quality

Per base sequence content

Sequence Length Distribution

Sequence Duplication Levels

Previously, I faced a problem with Nexttera Transposase sequences, but it was solved by using Trim-Galore as recommended,

1- So, Please give me your evaluation! Is it ok to use this reads for assembly!, or I should improve the quality!!, and how can I improve it!

2- Also, is it enough to assemble the paired reads, or I should also process unpaired ones as well!

Thank you for your time

sequencing genome next-gen • 1.3k views
ADD COMMENT
1
Entering edit mode

The link you posted is broken. I edited your title, please use short, meaningful titles in the future.

2- Also, is it enough to assemble the paired reads, or I should also process unpaired ones as well!

Depends on how much coverage you have, but generally, using just the paired ends is enough.

ADD REPLY
0
Entering edit mode

thanks, h.mon, I modified the post...

ADD REPLY
1
Entering edit mode

The images still appear to be broken. Please post correct links.

ADD REPLY
0
Entering edit mode

I re-uploaded the photos

ADD REPLY
1
Entering edit mode

Don't set an auto-delete time, if you were doing that.

BTW: Data looks reasonable. If the adapters are gone then you can try doing the assembly.

ADD REPLY
0
Entering edit mode

I Modified it again, thanks

ADD REPLY
1
Entering edit mode

1- So, how can I improve these results using galaxy tools, in which I can move to the assembly step

I don't know if you can provide custom sequences to trimmomatic via galaxy interface. But that would be the way to go to tackle.

Nextra Transposase sequences

I suggest that you use How to add images to a Biostars post to post images from FastQC report.

FastQC authors have some blog posts that are a good read to understand some of the observations you have noted.

ADD REPLY
0
Entering edit mode

thank you genomax for the link, it is very useful

ADD REPLY
1
Entering edit mode

Nextra Transposase sequences are still there

If you are using galaxy you could try trimgalore. This tool already has a parameter specifically for Nextra Transposase

ADD REPLY
0
Entering edit mode

Thank you gb, I used trim-galore and it successfully removed these adapters

ADD REPLY

Login before adding your answer.

Traffic: 2125 users visited in the last hour
Help About
FAQ
Access RSS
API
Stats

Use of this site constitutes acceptance of our User Agreement and Privacy Policy.

Powered by the version 2.3.6