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Fix per tile sequence quality?

I see the following FastQC results in the "Per tile sequence quality" module:

https://ibb.co/he9DBd

Compared to other threads and articles I have seen, this does not look so bad in comparisson, but I am not sure if I should try to fix it anyway, files have been already run through Trimmomatic for quality trimming and adapter removal.

Samples come from a Hiseq4000 machine.

Libraries were prepared using TruSeq Nano chemestry.

  • Could you give me some advise on how to proceed with these samples?

  • Also, I cannot get the y-axis: according to Illumina, there are 896 tiles in a flow cell. Are tiles binned (or skipped) by FastQC?

I appreaciate your contributions

Cheers!

fastqc dnaseq illumina quality control

1 answer

I suggest that you don't doing anything for now. Go ahead and proceed with the rest of your analysis. Tiles are not binned by FastQC, sequencing cycles are.

Thanks, do you have an idea why are there so much less tiles in the y-axis than tiles in the flow cell?

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