How much do i have to trimming the dada2

Hi this is my sample quality score and sequence lengh about
I did single end seqeuncing with ion torrent with v3-v4 region

from now i have really big question
Which percent of sample do i have to trimming the length..
please help me with this problem
thanks a lot

Hi @medhanlee0721
Have you taken a look at our youtube channel?
We have multiple videos going over trimming and truncing with dada2 in QIIME 2 that might be helpful for you.


yeah, i have been watched already before. but i didn't get my answer from there...

Hi @medhanlee0721,

I just wanted to jump in here with a friendly reminder that your work is your own. We cannot provide you with trim/truncation lengths for your data, as that is something that you must determine in your analysis.

With that being said, the videos on our Youtube channel that @cherman2 mentioned do discuss trim/trunc lengths based on quality scores, which is how I'd recommend you make your decision. Another great resource that discusses quality score based filtering using DADA2 is our Moving Pictures tutorial, which I'd recommend going through (if you haven't already).

One final resource I'd recommend is searching for 'selecting trim/trunc length in DADA2' on the forum - you'll find many threads regarding the same question that discuss how to make an informed decision on these parameters based on your interactive quality plot.

Hope this helps! Cheers :lizard: