Wierd demux quality score data using “Fastq manifest” formats, quality scores PHRED 33

I recently got Illumina-based 16s rRNA sequencing data.
I am trying to import my data using Fastq manifest format.
and the demultiplexed data is looking unusual.
"SingleEndFastqManifestPhred33V2" this variant was used to the procedure.
I am yet to finish the trimming process.but, when I am visualising it, the quality score graph looks weird.

why is it,
can somebody please assist me,
the quality score graph is attached below


Newer Illumina machines do bin quality scores (scores that are close together get assigned the same score) which leads to these graphs being a bit flatter with newer Illumina machines than with other machines, but still the quality scores being completely flat like that is a bit unusual. It's possible that you just got a really good run.

1 Like

This topic was automatically closed 31 days after the last reply. New replies are no longer allowed.