QA/QC Step

Processes raw FASTQ files (paired or single), provides quality plots, optional primer trimming, optional paired-end merging, and produces QIIME 2 demultiplexed artifacts plus QA summaries.

Inputs

Choose one in config_01_qaqc.yaml:

raw_fastq_path: /abs/path/to/raw_fastqs
trimmed_fastq_path: /abs/path/to/trimmed_fastqs
sample_manifest_file: 00-data/manifest_pe.csv
preexisting_fastq_qza: /abs/path/demux.qza

Set paired_end: true|false accordingly.

Manifest formats

TSV (current QIIME 2):

Paired-end:

sample-id   forward-absolute-filepath   reverse-absolute-filepath
sample1 /path/to/sample1_R1.fastq.gz    /path/to/sample1_R2.fastq.gz

Single-end:

sample-id   absolute-filepath
sample1 /path/to/sample1_R1.fastq.gz

CSV (legacy):

Paired-end:

sample-id,absolute-filepath,direction
sample1,/path/to/sample1_R1.fastq.gz,forward
sample1,/path/to/sample1_R2.fastq.gz,reverse

Single-end:

sample-id,absolute-filepath
sample1,/path/to/sample1_R1.fastq.gz

Optional trimming

to_trim: true
fwd_primer: ATCG...
rev_primer: ATCG...
discard_untrimmed: false
minimum_length: 100

Optional merging

to_merge: true
maxdiffs: 20
merge_stagger: --p-allowmergestagger

Outputs

  • Demultiplexed sequences (raw_fastq.qza or trimmed) and summary visualizations
  • Stats under [run_name]-qaqc/stats/ (raw summaries, trimmed summaries, merge stats when enabled, sequence-quality drop-off report)

Continue with Repseqs or run all via Running.