-Primers are trimmed in two steps using CUTADAPT v3.2 from bioconda (Martin, 2011). This step now uses the linked adapter approach to remove forward and reverse primers in one step. Primer sequences need to be specified in an adapters.fasta file and the user may wish to anchor them or not, see CUTADAPT manual for details https://cutadapt.readthedocs.io/en/stable/guide.html?highlight=linked#linked-adapters . At this step, CUTADAPT looks for a minimum Phred quality score of at least 20 at the ends, no more than 10% errors allowed in the primer, no more than 3 N's allowed in the rest of the sequence, trimmed reads need to be at least 150 bp, untrimmed reads are discarded. Each of these parameters are adjustable.
0 commit comments