Trobleshooting import reads

Dear Qiimers,

I am working on some unusual data for me, and I need some help with importing the reads correctly. I have 16S v3-v4 Illumina data, which seem to have been already demultiplexed and trimmed; also, looking at the headers, each sample was sequenced on multiple lanes, which were then merged. My usual:

qiime tools import --type 'SampleData[PairedEndSequencesWithQuality]' \
    --input-format CasavaOneEightLanelessPerSampleDirFmt 

does not work:
Missing one or more files for CasavaOneEightSingleLanePerSampleDirFmt: '.+_.+_L[0-9][0-9][0-9]_R[12]_001\\.fastq\\.gz'

So I tried
--input-format CasavaOneEightLanelessPerSampleDirFmt

The import step seemed to have worked, but then I got the same error in the next step (cutadapt).

Can you please advice on the best way to import the data?

Thank you for your kind attention,

EDIT: I am using q2 v 2019.7

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Hi @mstagliamonte,

Have you tried the manifest format? It requires a bit more work up front from you for importing, but I think it will make your life easier over all.

There’s some development for automatic manifests in both R and python which might be of interest.



Dear @jwdebelius ,

Thank you for your kind answer. Also the script for making manifest files is a great idea!
I was looking at the manifest file tutorial, and one of the fields requires the lane number. The files I received have already been merged by sample, so there are at least 2 lanes in each fastq file. Do you have any advice how to include this info on the manifest file? Or should I resort to split the reads by lane and then import them?


EDIT: Nevermind, I read thorugh the tutorial again, maybe I don’t need that column in the manifesto. I will give it a try and see how it goes. :slightly_smiling_face:


Yes the manifest file should look like this:

Code should look like this:

qiime tools import
--type 'SampleData[PairedEndSequencesWithQuality]'
--input-path /gpfs/scratch/wub02/projects/
--output-path /gpfs/scratch/wub02/projects/
--input-format PairedEndFastqManifestPhred33V2

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I have run ll the way to deblur and everything seems to work. Thank you for guiding me through it, I appreciate your kind help.



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