Understanding min sequence length of F and R/ quality scores and how it is impacting dada2 downstream

[colinbrislawn (Colin J Brislawn)]

Here are two threads related to this error:

DADA2 Denoising CCS error in learning error rates

Hi @Oddant1, I was trying to work on denoising step (a new set of samples). And it gives me following error. I tried with solutions for OOM and didn't' work. Looks like it is an error in dada2. Your help is much appreciated. Version of QIIME 2 you are running, and how it is installed (e.g. Virtualbox, conda, etc.) qiime2-amplicon-2024.2 Virtual Machine: WSL, Ubuntu What is the exact command or commands you ran? Copy and paste please. qiime dada2 denoise-ccs --i-demultiplexed-seqs r…

Plugin errors when running deblur and dada2 on large single-end 16S dataset

Hi Byron, I'm not very familiar with the DADA2 runtime. However, the error output in the log file states "Invalid derep$quals matrix. Quality values must be positive integers." This suggests one of the input files either has unusual PHRED scores, the PHRED offset being used is incorrect, or perhaps some other underlying issue. Best, Daniel

It sounds pretty rare! I'm not sure what's best here.

While you review the threads, let's see what the other mods have to say!